Substituted Indolealkanoic Acids

ABSTRACT

Disclosed are substituted indolealkanoic acids useful in the treatment of chronic complications arising from diabetes mellitus. Also disclosed are pharmaceutical compositions containing the compounds and methods of treatment employing the compounds, as well as methods for their synthesis.

This application is a continuation of application Ser. No. 12/701,967,filed on Feb. 8, 2010, which is a divisional of application Ser. No.11/999,524, filed on Dec. 4, 2007, now U.S. Pat. No. 7,659,269, which isa continuation of application Ser. No. 11/531,151, filed on Sep. 12,2006, now U.S. Pat. No. 7,304,079, which is a continuation ofapplication Ser. No. 10/832,724, filed on Apr. 27, 2004, now U.S. Pat.No. 7,105,514, which is a continuation of application Ser. No.10/185,863, filed on Jun. 28, 2002, now U.S. Pat. No. 6,730,794, whichis a continuation of application Ser. No. 09/818,808, filed on Mar. 27,2001, now U.S. Pat. No. 6,426,344, which is a continuation ofapplication Ser. No. 09/282,280, filed on Mar. 31, 1999, now U.S. Pat.No. 6,214,991, which claims priority from application Ser. No.60/080,143, filed Mar. 31, 1998.

BACKGROUND OF INVENTION

The use of aldose reductase inhibitors (ARIs) for the treatment ofdiabetic complications is well known. The complications arise fromelevated levels of glucose in tissues such as the nerve, kidney, retinaand lens that enters the polyol pathway and is converted to sorbitol viaaldose reductase. Because sorbitol does not easily cross cell membranes,it accumulates inside certain cells resulting in changes in osmoticpressure, alterations in the redox state of pyridine nucleotides (i.e.increased NADH/NAD⁺ ratio) and depleted intracellular levels ofmyoinositol. These biochemical changes, which have been linked todiabetic complications, can be controlled by inhibitors of aldosereductase.

The use of aldose reductase inhibitors for the treatment of diabeticcomplications has been extensively reviewed, see: (a) Textbook ofDiabetes, 2nd ed.; Pickup, J. C. and Williams, G. (Eds.); BlackwellScience, Boston, Mass. 1997; (b) Larson, E. R.; Lipinski, C. A. andSarges, R., Medicinal Research Reviews, 1988, 8 (2), 159-198; (c)Dvornik, D. Aldose Reductase Inhibition. Porte, D. (ed), BiomedicalInformation Corp., New York, N.Y. Mc Graw Hill 1987; (d) Petrash, J. M.,Tarle, I., Wilson, D. K. Quiocho. F. A. Perspectives in Diabetes, AldoseReductase Catalysis and Crystalography: Insights From Recent Advances inEnzyme Structure and Function, Diabetes, 1994, 43, 955; (e) Aotsuka, T.;Abe, N.; Fukushima, K.; Ashizawa, N. and Yoshida, M., Bioorg. & Med.Chem. Letters, 1997, 7, 1677, (f), T., Nagaki, Y.; Ishii, A.; Konishi,Y.; Yago, H; Seishi, S.; Okukado, N.; Okamoto, K., J. Med. Chem., 1997,40, 684; (g) Ashizawa, N.; Yoshida, M.; Sugiyama, Y.; Akaike, N.;Ohbayashi, S.; Aotsuka, T.; Abe, N.; Fukushima, K.; Matsuura, A, Jpn. J.Pharmacol. 1997, 73, 133; (h) Kador, P. F.; Sharpless, N. E., MolecularPharmacology, 1983, 24, 521; (I) Kador, P. F.; Kinoshita, J. H.;Sharpless, N. E., J. Med. Chem. 1985, 28 (7), 841; (j) Hotta, N.,Biomed. & Pharmacother. 1995, 5, 232; (k) Mylar, B.; Larson, E. R.;Beyer, T. A.; Zembrowski, W. J.; Aldinger, C. E.; Dee, F. D.; Siegel, T.W.; Singleton, D. H., J. Med. Chem. 1991, 34, 108; (l) Dvornik, D.Croatica Chemica Acta 1996, 69 (2), 613.

Previously described aldose reductase inhibitors most closely related tothe present invention include those sighted in: (a) U.S. Pat. No.5,700,819: 2-Substituted benzothiazole derivatives useful in thetreatment of diabetic complications, (b) U.S. Pat. No. 4,868,301:Processes and intermediates for the preparation of oxophthalazinylacetic acids having benzothiazole or other heterocyclic side chains, (c)U.S. Pat. No. 5,330,997: 1H-indazole-3-acetic acids as aldose reductaseinhibitors, and (d) U.S. Pat. No. 5,236,945: 1H-indazole-3-acetic acidsas aldose reductase inhibitors. Although many aldose reductaseinhibitors have been extensively developed, none have demonstratedsufficient efficacy in human clinical trials without significantundesirable side effects. Thus no aldose reductase inhibitors arecurrently available as approved therapeutic agents in the United States;and consequently, there is still a significant need for new, efficaciousand safe medications for the treatment of diabetic complications.

SUMMARY OF THE INVENTION

This invention provides compounds that interact with and inhibit aldosereductase. Thus, in a broad aspect, the invention provides compounds ofFormula I:

or pharmaceutically acceptable salts thereof wherein

-   A is a C₁-C₄ alkylene group optionally substituted with C₁-C₂ alkyl    or mono- or disubstituted with halogen, preferably fluoro or chloro;-   Z is a bond, O, S, C(O)NH, or C₁-C₃ alkylene optionally substituted    with C₁-C₂ alkyl;-   R₁ is hydrogen, alkyl having 1-6 carbon atoms, halogen, 2-, 3-, or    4-pyridyl, or phenyl, where the phenyl or pyridyl is optionally    substituted with up to three groups selected from halogen, hydroxy,    C₁-C₆ alkoxy, C₁-C₆ alkyl, nitro, amino, or mono- or    di(C₁-C₆)alkylamino;-   R₂, R₃, R₄ and R₅ are each independently hydrogen, halogen, nitro,    or an alkyl group of 1-6 carbon atoms (which may be substituted with    one or more halogens);-   OR₇, SR₇, S(O)R₇, S(O)₂(R₇)₂, C(O)N(R₇)₂, or N(R₇)₂, wherein each R₇    is independently hydrogen, an alkyl group of 1-6 carbon atoms (which    may be substituted with one or more halogens) or benzyl, where the    phenyl portion is optionally substituted with up to three groups    independently selected from halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy,    amino, and mono- or di(C₁-C₆)alkylamino; phenyl or heteroaryl such    as 2-, 3- or 4-imidazolyl or 2-, 3-, or 4-pyridyl, each of which    phenyl or heteroaryl is optionally substituted with up to three    groups independently selected from halogen, C₁-C₆ alkyl, C₁-C₆    alkoxy, amino, and mono- or di(C₁-C₆)alkylamino;-   phenoxy where the phenyl portion is optionally substituted with up    to three groups independently selected from halogen, C₁-C₆ alkyl,    C₁-C₆ alkoxy, amino, and mono- or di(C₁-C₆)alkylamino; or-   a group of the formula

-   -   where        -   J is a bond, CH₂, oxygen, or nitrogen; and        -   each r is independently 2 or 3;

-   R₆ is hydroxy or a prodrug group;

-   R_(a) is hydrogen, C₁-C₆ alkyl, fluoro, or trifluoromethyl; and

-   Ar represents aryl or heteroaryl, each of which is optionally    substituted with up to five groups.

In another aspect, the invention provides methods for preparing suchcompounds.

The compounds of the invention inhibit aldose reductase. Since aldosereductase is critical to the production of high levels of sorbitol inindividuals with diabetes, inhibitors of aldose reductase are useful inpreventing and/or treating various complications associated withdiabetes. The compounds of the invention are therefore effective for thetreatment of diabetic complications as a result of their ability toinhibit aldose reductase.

Thus, in another aspect, the invention provides methods for treatingand/or preventing chronic complications associated with diabetesmellitus, including, for example, diabetic cataracts, retinopathy,nephropathy, and neuropathy.

In still another aspect, the invention provides pharmaceuticalcompositions containing compounds of Formula I.

DETAILED DESCRIPTION OF THE INVENTION

The numbering system for the compounds of Formula I is as follows:

As noted above, the invention provides novel substituted indole alkanoicacids useful in treating and/or preventing complications associated withor arising from elevated levels of glucose in individuals suffering fromdiabetes mellitus. These compounds are represented by Formula I above.

In compounds of Formula I, the aryl and heteroaryl groups represented byAr include:

-   a phenyl group optionally substituted with up to 5 groups    independently selected from halogen, an alkyl group of 1-6 carbon    atoms (which may be substituted with one or more halogens), nitro,    OR₇, SR₇, S(O)R₇, S(O)₂R₇ or N(R₇)₂ wherein R₇ is hydrogen, an alkyl    group of 1-6 carbon atoms (which may be substituted with one or more    halogens) or benzyl, where the phenyl portion is optionally    substituted with up to three groups independently selected from    halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, amino, and mono- or    di(C₁-C₆)alkylamino, or the phenyl group may be condensed with benzo    where the benzo is optionally substituted with one or two of    halogen, cyano, nitro, trifluoromethyl, perfluoroethyl,    trifluoroacetyl, or (C₁-C₆)alkanoyl, hydroxy, (C₁-C₆)alkyl,    (C₁-C₆)alkoxy, (C₁-C₆)alkylthio, trifluoromethoxy,    trifluoromethylthio, (C₁-C₆)alkylsulfinyl, (C₁-C₆)alkylsulfonyl;-   a heterocyclic 5-membered ring having one nitrogen, oxygen or    sulfur, two nitrogens one of which may be replaced by oxygen or    sulfur, or three nitrogens one of which may be replaced by oxygen or    sulfur, said heterocyclic 5-membered ring substituted by one or two    fluoro, chloro, (C₁-C₆)alkyl or phenyl, or condensed with benzo, or    substituted by one of pyridyl, furyl or thienyl, said phenyl or    benzo optionally substituted by one of iodo, cyano, nitro,    perfluoroethyl, trifluoroacetyl, or (C₁-C₆)alkanoyl, one or two of    fluoro, chloro, bromo, hydroxy, (C₁-C₆)alkyl, (C₁-C₆)alkoxy,    (C₁-C₆)alkylthio, trifluoromethoxy, trifluoromethylthio,    (C₁-C₆)alkylsulfinyl, (C₁-C₆)alkylsulfonyl or trifluoromethyl, or    two fluoro or two trifluoromethyl with one hydroxy or one    (C₁-C₆)alkoxy, or one or, preferably, two fluoro and one    trifluoromethyl, or three fluoro, said pyridyl, furyl or thienyl    optionally substituted in the 3-position by fluoro, chloro, bromo,    (C₁-C₆)alkyl or (C₁-C₆)alkoxy;-   a heterocyclic 6-membered ring having one to three nitrogen atoms,    or one or two nitrogen atoms and one oxygen or sulfur, said    heterocyclic 6-membered ring substituted by one or two (C₁-C₆)alkyl    or phenyl, or condensed with benzo, or substituted by one of    pyridyl, furyl or thienyl, said phenyl or benzo optionally    substituted by one of iodo or trifluoromethylthio, or one or two of    fluoro, chloro, bromo, (C₁-C₆)alkyl, (C₁-C₆)alkoxy,    (C₁-C₆)alkylthio, (C₁-C₆)alkylsulfinyl, (C₁-C₆)alkylsulfonyl, or    trifluoromethyl, and said pyridyl, furyl or thienyl optionally    substituted in the 3-position by fluoro, chloro, (C₁-C₆)alkyl or    (C₁-C₆)alkoxy;-   said benzo-condensed heterocyclic 5-membered or 6-membered rings    optionally substituted in the heterocyclic 5-membered or 6-membered    ring by one of fluoro, chloro, bromo, methoxy, or trifluoromethyl;-   oxazole or thiazole condensed with a 6-membered aromatic group    containing one or two nitrogen atoms, with thiophene or with furane,    each optionally substituted by one of fluoro, chloro, bromo,    trifluoromethyl, methylthio or methylsulfinyl;-   imidazolopyridine or triazolopyridine optionally substituted by one    of trifluoromethyl, trifluoromethylthio, bromo, or (C₁-C₆)alkoxy, or    two of fluoro or chloro;-   thienothiophene or thienofuran optionally substituted by one of    fluoro, chloro or trifluoromethyl; thienotriazole optionally    substituted by one of chloro or trifluoromethyl;-   naphthothiazole; naphthoxazole; or thienoisothiazole.

More specific compounds of the invention are those of Formula I whereinAr is optionally substituted benzothiazolyl, benzoxazolyl, isoquinolyl,benzothiophen-yl, benzofuran-yl or benzimidazolyl, or substitutedoxadiazolyl or indolyl. Other more specific compounds are of Formula Ithose wherein R_(a) is trifluoromethyl, Z is a covalent bond or CH₂, R₆is hydroxy, and each of R₂-R₅ are independently hydrogen, halogen, morepreferably bromo or chloro, C₁-C₂ alkyl, phenoxy, benzyloxy, or C₁-C₂alkoxy, and R₁ is hydrogen or methyl.

Preferred compounds of the invention are those wherein Z is a covalentbond, R₆ is hydroxy, Ar is optionally substituted benzothiazol-2-yl,benzothiazol-5-yl, benzoisothiazol-3-yl, benzoxazol-2-yl, 2-quinolyl,2-quinoxalyl, oxazolo[4,5-b]pyridine-2-yl, benzothiophen-2-yl,benzofuran-2-yl, or thazolo[4,5-pyridine-2-y,thieno[2,3-b]pyridine-2-yl, imidazo[1,5-a]pyridine-2-yl, or indol-2-yl,or substituted 1,2,4-oxadiazol-3-yl, 1,2,4-oxadiazol-5-yl,isothiazol-5-yl, isothiazol-4-yl, 1,3,4-oxadiazol-5-yl,1,2,5-thiadiazol-3-yl, oxazol-2-yl, thiazol-2-yl, or thiazol-4-yl, R₂-R₅are independently hydrogen, halogen, more preferably bromo or chloro,C₁-C₂ alkyl, phenoxy, benzyloxy or phenyl where each phenyl portion isoptionally substituted with C₁-C₆ alkyl, halogen, C₁-C₆ alkoxy, hydroxy,amino or mono- or di(C₁-C₆)alkylamino R_(a) is hydrogen, fluoro or C₁-C₂alkyl, and R₁ is hydrogen or methyl.

Other preferred compounds are those wherein the methylene bridgeconnecting the indolyl group with Ar is located alpha with respect to anitrogen atom in Ar, e.g. wherein Ar is benzoxazol-2-yl or1,2,4-oxadiazol-3-yl mentioned above.

Other more specific compounds of the invention are those wherein Z is acovalent bond, R₆ is hydroxy, R_(a) is hydrogen, Ar is optionally 4,5,6or 7 benzo-substituted benzothiazolyl, benzoxazolyl, benzimidazolyl,benzothiophenyl, benzofuranyl, or indolyl, or Ar is 2-benzothiazolylsubstituted on benzo by one trifluoroacetyl or trifluoromethylthio, orone or two of fluoro chloro, bromo, hydroxy, methyl, methoxy,trifluoromethyl, trifluoromethoxy, trifluoromethylthio, or one or,preferably, two fluoro and one trifluoromethyl, or two fluoro or twotrifluoromethyl with one methoxy, or three fluoro, or by 6,7-benzo, andthose wherein one of R₂ and R₃ is hydrogen, fluoro, chloro, bromo ormethyl, and one of R₄ and R₅ is hydrogen, or chloro, bromo, methyl,isopropyl, methoxy, nitro or trifluoromethyl; or R₃ and R₄ is5,6-difluoro, R_(a) is hydrogen; and those wherein Ar is optionallysubstituted benzothiazol-2-yl or quinoxalyl and R₃ and R₄ are eachchloro, and R₁ is hydrogen or methyl.

Further more specific compounds are those wherein Z is a covalent bond,R₆ is hydroxy, Ar is optionally substituted benzothiazol-2-yl, R₃ and R₄are hydrogen, and R₅ is methyl; those wherein Z is a covalent bond, R₆is hydroxy, R₃, R₄ and R₅ are hydrogen, chloro, fluoro, bromo or C₁-C₂alkyl, R_(a) is hydrogen, and Ar is optionally 4,5,6 or 7benzosubstituted benzothiazolyl-2-trifluoromethyl,benzoxazolyl-2-trifluoromethyl, benzimidazolyl-2-trifluoromethyl,benzofuran-2-trifluoromethyl, benzofuran-3-trifluoromethyl,benzothiophen-2-trifluoromethyl, benzothiophen-3-trifluoromethyl,indolyl-2-trifluoromethyl, or indolyl-3-trifluoromethyl; and thosewherein Z is CH₂, R₆ is hydroxy, Ar is optionally substitutedbenzothiazol-2-yl, benzothiazol-5-yl, benzoisothiazol-3-yl,benzoxazol-2-yl, 2-quinolyl, 2-quinoxalyl, oxazolo[4,5-b]pyridine-2-yl,or thiazolo[4,5-b]pyridine-2-yl, or substituted 1,2,4-oxadiazol3-yl,1,2,4-oxadiazol-5-yl, isothiazol-5-yl, isothiazol-4-yl,1,3,4-oxadiazol-5-yl, 1,2,5-thiadiazol-3-yl, oxazol-2-yl, thiazol-2-yl,or thiazol-4-yl, and R₃, R₄ and R₅ are independently hydrogen, chloro,fluoro, bromo, C₂-C₂ alkyl, or trifluoromethyl, and R_(a) is hydrogen.

Generally, R₁ in the specific compounds described above is hydrogen,halogen, preferably chloro or fluoro, C₁-C₆ alkyl, or phenyl optionallysubstituted with up to three groups independently selected from halogen,C₁-C₆ alkyl, C₁-C₆ alkoxy, amino, and mono- or di(C₁-C₆)alkylamino.Preferred R₁ groups are hydrogen and methyl.

Preferred compounds of the invention include those where Ar in Formula Iis substituted phenyl, i.e., compounds of Formula II:

wherein

-   A is a C₁-C₄ alkylene group optionally substituted with C₁-C₂ alkyl;-   Z is a bond, or C₁-C₃ alkylene optionally substituted with C₁-C₂    alkyl;-   R_(a) is hydrogen, C₁-C₆ alkyl, chloro, bromo, fluoro, or    trifluoromethyl;-   R₁ is hydrogen, C₁-C₆ alkyl, fluoro, or phenyl optionally    substituted with up to three groups independently selected from    halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, amino, and mono- or    di(C₁-C₆)alkylamino;-   R₂, R₃, R₄ and R₅ are each independently    -   hydrogen, halogen, an alkyl group of 1-6 carbon atoms (which may        be substituted with one or more halogens), nitro, OR₇, SR₇,        S(O)R₇, S(O)₂N(R₇)₂, C(O)N(R₇)₂, or N(R₇)₂, wherein each R₇ is        independently hydrogen, an alkyl group of 1-6 carbon atoms        (which may be substituted with one or more halogens) or benzyl,        where the phenyl portion is optionally substituted with up to        three groups independently selected from halogen, C₁-C₆ alkyl,        C₁-C₆ alkoxy, amino, and mono- or di(C₁-C₆)alkylamino;    -   phenyl or heteroaryl such as 2-, 3- or 4-imidazolyl or 2-, 3-,        or 4-pyridyl, each of which phenyl or heteroaryl is optionally        substituted with up to three groups independently selected from        halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, amino, and mono- or        di(C₁-C₆)alkylamino;    -   phenoxy where the phenyl portion is optionally substituted with        up to three groups independently selected from halogen, C₁-C₆        alkyl, C₁-C₆ alkoxy, amino, and mono- or di(C₁-C₆)alkylamino; or    -   a group of the formula

-   -   -   where            -   J is a bond, CH₂, oxygen, or nitrogen; and            -   each r is independently 2, or 3;

-   R₆ is hydrogen, an alkoxy group of 1-6 carbon atoms, or —O⁻M⁺ where    M⁺ is a cation forming a pharmaceutically acceptable salt; and

-   R₈, R₉, and R₁₀ are independently hydrogen, fluorine, chlorine,    bromine, trifluoromethyl or nitro.

Other preferred compounds of the invention are those where Ar is asubstituted benzothiazole, i.e., compounds of Formula III:

wherein

-   A is a C₁-C₄ alkylene group optionally substituted with C₁-C₂ alkyl;-   Z is a bond, or C₁-C₃ alkylene optionally substituted with C₁-C₂    alkyl;-   R_(a) is hydrogen, C₁-C₆ alkyl, chloro, bromo, fluoro, or    trifluoromethyl;-   R₁ is hydrogen, C₁-C₆ alkyl, halogen, preferably chloro or fluoro,    or phenyl optionally substituted with up to three groups    independently selected from halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy,    amino, and mono- or di(C₁-C₆)alkylamino;-   R₂, R₃, R₄ and R₅ are each independently hydrogen, halogen, an alkyl    group of 1-6 carbon atoms (which may be substituted with one or more    halogens), nitro, OR₇, SR₇, S(O)R₇, S(O)₂N(R₇)₂, C(O)N(R₇)₂ or    N(R₇)₂, wherein each R₇ is independently hydrogen, an alkyl group of    1-6 carbon atoms (which may be substituted with one or more    halogens) or benzyl, where the phenyl portion is optionally    substituted with up to three groups independently selected from    halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, amino, and mono- or    di(C₁-C₆)alkylamino;    -   phenyl or heteroaryl such as 2-, 3- or 4-imidazolyl or 2-, 3-,        or 4-pyridyl, each of which phenyl or heteroaryl is optionally        substituted with up to three groups independently selected from        halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, amino, and mono- or        di(C₁-C₆)alkylamino;    -   phenoxy where the phenyl portion is optionally substituted with        up to three groups independently selected from halogen, C₁-C₆        alkyl, C₁-C₆ alkoxy, amino, and mono- or di(C₁-C₆)alkylamino; or    -   a group of the formula

-   -   -   where            -   J is a bond, CH₂, oxygen, or nitrogen; and            -   each r is independently 2 or 3;

-   R₆ is hydroxy, C₁-C₆ alkoxy, or —O⁻M⁺ where M⁺ is a cation forming a    pharmaceutically acceptable salt; and

-   R₁₁, R₁₂, R₁₃ and R₁₄ are independently hydrogen, halogen, nitro,    hydroxy, C₁-C₆ alkyl, C₁-C₆ alkoxy, C₁-C₆ alkylthio,    trifluoromethyl, trifluoromethoxy, C₁-C₆ alkylsulfinyl, or C₁-C₆    alkylsulfonyl.

In preferred compounds of Formula III, the R₂, R₃, R₄ and R₅substituents, in combination, represent one of bromo, cyano or nitro,one or two of fluoro, chloro, hydroxy, (C₁-C₆)alkyl, (C₁-C₆)alkoxy, ortrifluoromethyl, or two fluoro or two methyl with one hydroxy or one(C₁-C₆)alkoxy, or one or, preferably, two fluoro and one methyl, orthree fluoro groups. Particularly preferred R₂, R₃, R₄ and R₅substituents are, independently, fluorine, chlorine, nitro, andtrifluoromethyl.

In preferred compounds of Formulas II and III, A is preferablymethylene, methylene substituted with a methyl group, or ethylene.

Preferred compounds according to Formula II above include those whereinR₈ is fluorine, R₉ is hydrogen and R₁₀ is bromine or those wherein R₈and R₁₀ are hydrogens and R₉ is nitro.

Preferred compounds of Formula III above are thosewherein thebenzothiazole moiety is substituted with nitro, one, two, or three offluoro, one or two of chloro, or at least one trifluoromethyl group.More preferred compounds of Formula II are those where A is methylene,R₁ is hydrogen or methyl, Z is a bond, and R₆ is hydroxy or C₁-C₆alkoxy.

Still more preferred compounds of Formula II are those wherein R₁₁, R₁₂and R₁₄ are fluorines and R₁₃ is hydrogen. Other more preferredcompounds of Formula II are those where R_(a) is methyl or hydrogen, Zis methylene or, more preferably, a bond, A is CHF or C₁ or C₂ alkylene,preferably methylene, R₁ is methyl or hydrogen, and R₁₁, R₁₂ and R₁₄ arehalogens or C₁-C₃ alkyl. Still other more preferred compounds of FormulaIII are those where R_(a) is methyl or hydrogen, Z is methylene or, morepreferably, a bond, A is CHF or C₁ or C₂ alkylene, R₁ is methyl orhydrogen, and R₁₁, R₁₂ and R₁₄ are fluorines or chlorines.

Particularly preferred compounds of Formula I are those where R₃ and R₄are independently hydrogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, or halogen, andR_(a) is methyl or hydrogen, Z is a bond, A is methylene, methylsubstituted methylene, or ethylene, R₁ is methyl or hydrogen, and R₁₁,R₁₂ and R₁₄ are fluorines or chlorines.

The term “prodrug group” denotes a moiety that is converted in vivo intothe active compound of formula I wherein R₆ is hydroxy. Such groups aregenerally known in the art and include ester forming groups, to form anester prodrug, such as benzyloxy, di(C₁-C₆)alkylaminoethyloxy,acetoxymethyl, pivaloyloxymethyl, phthalidoyl, ethoxycarbonyloxyethyl,5-methyl-2-oxo-1,3-dioxol-4-yl methyl, and (C₁-C₆)alkoxy optionallysubstituted by N-morpholino and amide-forming groups such asdi(C₁-C₆)alkylamino. Preferred prodrug groups include hydroxy, C₁-C₆alkoxy, and O⁻M⁺ where M⁺ represents a cation. Preferred cations includesodium, potassium, and ammonium. Other cations include magnesium andcalcium. Further preferred prodrug groups include O⁼M⁺⁺ where M⁺⁺ is adivalent cation such as magnesium or calcium.

In certain situations, compounds of Formula I may contain one or moreasymmetric carbon atoms, so that the compounds can exist in differentstereoisomeric forms. These compounds can be, for example, racemates oroptically active forms. In these situations, the single enantiomers,i.e., optically active forms, can be obtained by asymmetric synthesis orby resolution of the racemates. Resolution of the racemates can beaccomplished, for example, by conventional methods such ascrystallization in the presence of a resolving agent, or chromatography,using, for example a chiral HPLC column.

Representative compounds of the present invention include thepharmaceutically acceptable acid addition salts of compounds where R₆includes basic nitrogen atom, i.e, an alkylamino or morpholino group. Inaddition, if the compound or prodrug of the invention is obtained as anacid addition salt, the free base can be obtained by basifying asolution of the acid salt. Conversely, if the product is a free base, anaddition salt, particularly a pharmaceutically acceptable addition salt,may be produced by dissolving the free base in a suitable organicsolvent and treating the solution with an acid, in accordance withconventional procedures for preparing acid addition salts from basecompounds.

Non-toxic pharmaceutical salts include salts of acids such ashydrochloric, phosphoric, hydrobromic, sulfuric, sulfinic, formic,toluenesulfonic, methanesulfonic, nitric, benzoic, citric, tartaric,maleic, hydroiodic, alkanoic such as acetic, HOOC—(CH₂)n-ACOOH where nis 0-4, and the like. Non-toxic pharmaceutical base addition saltsinclude salts of bases such as sodium, potassium, calcium, ammonium, andthe like. Those skilled in the art will recognize a wide variety ofnon-toxic pharmaceutically acceptable addition salts.

As used herein, the terms 2-benzothiazolyl and benzothiazol-2-yl aresynonymous.

Representative groups of the formula

include those where J is oxygen and each r is 2 (morpholinyl), J isnitrogen and each r is 2 (piperazinyl) or one r is 2 and the other 3(homopiperazinyl), or J is CH₂ and each r is 2 (piperidinyl) or one r is2 and the other 3 (homopiperidinyl). Preferred groups of this formulaare morpholinyl and piperazinyl.

The heterocyclic 5-membered ring having one to three nitrogen atoms, oneof which may be replaced by oxygen or sulfur includes imidazolyl,oxazolyl, triazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, andtriazolyl.

The heterocyclic 6-membered ring having one to three nitrogen atoms, orone or two nitrogen atoms and one oxygen or sulfur includes triazinyl,pyrimidyl, pyridazinyl, oxazinyl and triazinyl.

The heterocyclic ring may be condensed with benzo so that said ring isattached at two neighboring carbon atoms to form a phenyl group. Suchbenzoheterocyclic ring may be attached to Z either through theheterocyclic group or through the benzo group of the benzoheterocyclicring. Specific wherein said heterocyclic ring is condensed with a benzoinclude benzoxazolyl, quinazolin-2-yl, 2-benzimidazolyl, quinazolin-4-yland benzothiazolyl. The oxazole or thiazole condensed with a 6-memberedaromatic group containing one or two nitrogen atoms include positionalisomers such as oxazolo[4,5-b]pyridine-2-yl,thiazolo[4,5-b]pyridine-2-yl, oxazolo[4,5-c]pyridine-2-yl,thiazolo[4,5-c]pyridine-2-yl, oxazolo[5,4-b]pyridine-2-yl,thiazolo[5,4-b]pyridine-2-yl, oxazolo[5,4-c]pyridine-2-yl, andthiazolo[5,4-c]pyridine-2-yl.

The following compounds of the invention are provided to give the readeran understanding of the compounds encompassed by the invention:

-   3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid-   5-chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   2-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   5-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   7-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   6-chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   5-benzyloxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   6-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   5-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   6-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic    acid-   3-methyl(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-2    propionic acid-   3-methyl(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-3    propionic acid-   3-(5-trifluoromethylbenzothiazol-2-yl)methyl-indole-N-acetic acid-   5-methyl-3-(5-trifluoromethylbenzothiazol-2-yl)methyl-indole-N-acetic    acid-   3-(3-nitrophenyl)methyl-indole-N-acetic Acid

The above compounds, further described in the Examples and otherdescription of the invention below, are illustrative but are not meantto limit in any way the scope of the contemplated compounds according tothe present invention.

The compounds of general Formula I may be administered orally,topically, parenterally, by inhalation or spray or rectally in dosageunit formulations containing conventional non-toxic pharmaceuticallyacceptable carriers, adjuvants and vehicles. The term parenteral as usedherein includes subcutaneous injections, intravenous, intramuscular,intrasternal injection or infusion techniques. In addition, there isprovided a pharmaceutical formulation comprising a compound of generalFormula I and a pharmaceutically acceptable carrier. One or morecompounds of general Formula I may be present in association with one ormore non-toxic pharmaceutically acceptable carriers and/or diluentsand/or adjuvants and if desired other active ingredients. Thepharmaceutical compositions containing compounds of general Formula Imay be in a form suitable for oral use, for example, as tablets,troches, lozenges, aqueous or oily suspensions, dispersible powders orgranules, emulsion, hard or soft capsules, or syrups or elixirs.

Compositions intended for oral use may be prepared according to anymethod known to the art for the manufacture of pharmaceuticalcompositions and such compositions may contain one or more agentsselected from the group consisting of sweetening agents, flavoringagents, coloring agents and preserving agents in order to providepharmaceutically elegant and palatable preparations. Tablets contain theactive ingredient in admixture with non-toxic pharmaceuticallyacceptable excipients which are suitable for the manufacture of tablets.These excipients may be for example, inert diluents, such as calciumcarbonate, sodium carbonate, lactose, calcium phosphate or sodiumphosphate; granulating and disintegrating agents, for example, cornstarch, or alginic acid; binding agents, for example starch, gelatin oracacia, and lubricating agents, for example magnesium stearate, stearicacid or talc. The tablets may be uncoated or they may be coated by knowntechniques to delay disintegration and absorption in thegastrointestinal tract and thereby provide a sustained action over alonger period. For example, a time delay material such as glycerylmonostearate or glyceryl distearate may be employed.

Formulations for oral use may also be presented as hard gelatin capsuleswherein the active ingredient is mixed with an inert solid diluent, forexample, calcium carbonate, calcium phosphate or kaolin, or as softgelatin capsules wherein the active ingredient is mixed with water or anoil medium, for example peanut oil, liquid paraffin or olive oil.

Aqueous suspensions contain the active materials in admixture withexcipients suitable for the manufacture of aqueous suspensions. Suchexcipients are suspending agents, for example sodiumcarboxymethylcellulose, methylcellulose, hydropropylmethylcellulose,sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia;dispersing or wetting agents may be a naturally-occurring phosphatide,for example, lecithin, or condensation products of an alkylene oxidewith fatty acids, for example polyoxyethylene stearate, or condensationproducts of ethylene oxide with long chain aliphatic alcohols, forexample heptadecaethyleneoxycetanol, or condensation products ofethylene oxide with partial esters derived from fatty acids and ahexitol such as polyoxyethylene sorbitol monooleate, or condensationproducts of ethylene oxide with partial esters derived from fatty acidsand hexitol anhydrides, for example polyethylene sorbitan monooleate.The aqueous suspensions may also contain one or more preservatives, forexample ethyl, or n-propyl p-hydroxybenzoate, one or more coloringagents, one or more flavoring agents, and one or more sweetening agents,such as sucrose or saccharin.

Oily suspensions may be formulated by suspending the active ingredientsin a vegetable oil, for example arachis oil, olive oil, sesame oil orcoconut oil, or in a mineral oil such as liquid paraffin. The oilysuspensions may contain a thickening agent, for example beeswax, hardparaffin or cetyl alcohol. Sweetening agents such as those set forthabove, and flavoring agents may be added to provide palatable oralpreparations. These compositions may be preserved by the addition of ananti-oxidant such as ascorbic acid.

Dispersible powders and granules suitable for preparation of an aqueoussuspension by the addition of water provide the active ingredient inadmixture with a dispersing or wetting agent, suspending agent and oneor more preservatives. Suitable dispersing or wetting agents andsuspending agents are exemplified by those already mentioned above.Additional excipients, for example sweetening, flavoring and coloringagents, may also be present.

Pharmaceutical compositions of the invention may also be in the form ofoil-in-water emulsions. The oily phase may be a vegetable oil, forexample olive oil or arachis oil, or a mineral oil, for example liquidparaffin or mixtures of these. Suitable emulsifying agents may benaturally-occurring gums, for example gum acacia or gum tragacanth,naturally-occurring phosphatides, for example soy bean, lecithin, andesters or partial esters derived from fatty acids and hexitol,anhydrides, for example sorbitan monoleate, and condensation products ofthe said partial esters with ethylene oxide, for example polyoxyethylenesorbitan monoleate. The emulsions may also contain sweetening andflavoring agents.

Syrups and elixirs may be formulated with sweetening agents, for exampleglycerol, propylene glycol, sorbitol or sucrose. Such formulations mayalso contain a demulcent, a preservative and flavoring and coloringagents. The pharmaceutical compositions may be in the form of a sterileinjectable aqueous or oleaginous suspension. This suspension may beformulated according to the known art using those suitable dispersing orwetting agents and suspending agents which have been mentioned above.The sterile injectable preparation may also be sterile injectablesolution or suspension in a non-toxic parentally acceptable diluent orsolvent, for example as a solution in 1,3-butanediol. Among theacceptable vehicles and solvents that may be employed are water,Ringer's solution and isotonic sodium chloride solution. In addition,sterile, fixed oils are conventionally employed as a solvent orsuspending medium. For this purpose any bland fixed oil may be employedincluding synthetic mono- or diglycerides. In addition, fatty acids suchas oleic acid find use in the preparation of injectables.

The compounds of general Formula I may also be administered in the formof suppositories for rectal administration of the drug. Thesecompositions can be prepared by mixing the drug with a suitablenon-irritating excipient which is solid at ordinary temperatures butliquid at the rectal temperature and will therefore melt in the rectumto release the drug. Such materials are cocoa butter and polyethyleneglycols.

Compounds of general Formula I may be administered parenterally in asterile medium. The drug, depending on the vehicle and concentrationused, can either be suspended or dissolved in the vehicle.Advantageously, adjuvants such as local anesthetics, preservatives andbuffering agents can be dissolved in the vehicle.

Dosage levels on the order of from about 0.1 mg to about 140 mg perkilogram of body weight per day are useful in the treatment of theabove-indicated conditions (about 0.5 mg to about 7 g per patient perday). The amount of active ingredient that may be combined with thecarrier materials to produce a single dosage form will vary dependingupon the host treated and the particular mode of administration. Dosageunit forms will generally contain between from about 1 mg to about 1000mg of an active ingredient.

It will be understood, however, that the specific dose level for anyparticular patient will depend upon a variety of factors including theactivity of the specific compound employed, the age, body weight,general health, sex, diet, time of administration, route ofadministration, and rate of excretion, drug combination and the severityof the particular disease undergoing therapy.

The compounds of the present invention may be prepared by use of knownchemical reactions and procedures. General methods for synthesizing thecompounds are presented below. It is understood that the nature of thesubstituents required for the desired target compound often determinesthe preferred method of synthesis. All variable groups of these methodsare as described in the generic description if they are not specificallydefined below. More detailed procedures for particular examples arepresented below in the experimental section.

Methods of Preparation

The compounds of the invention where Ar is benzothiazolyl can beconveniently prepared from a substituted indole moiety using generalScheme A set forth below.

Treatment of a nitrile indole IV with a strong base such as, forexample, sodium hydride, butyl lithium or sodium tert-butoxide, in apolar aprotic solvent such as acetonitrile, tetrahydrofuran orN,N-dimethylformamide followed by an treatment with an alkylating agent,e.g., ethyl or tert-butyl bromoacetate, provides the desired N-alkylatedproduct V. Alternatively, phase transfer catalysis can be used in abiphasic solvent system. A general review of such alkylations can befound in Sundberg, R. J. Indoles; Chapter 11, Academic Press Inc., SanDiego, Calif., 1996. Condensation with a suitable 2-amino thiophenolhydrochloride salt VI provides benzothiazole intermediate VII. Thesereactions are most often carried out in an alcohol solvents at elevatedtemperatures; however, other solvents like N,N-dimethylformamide andN-methylpyrrolidone can be used or the reactions can be carried out inthe absence of solvents altogether. The scope of the reaction conditionsuseful for this transformation have been described previously (U.S. Pat.No. 5,700,819). General methods for the preparation of varioussubstituted 2-amino thiophenols are also well known (J. Med. Chem. 1991,34, 108 and Chem. Pharm. Bull. 1994, 42, 1264). In general, the bestmethod of synthesis is determined by such factors as availability ofstarting materials and ease of synthesis. Deprotection of the alkanoicacid moiety VII can be carried out by methods common to those skilled inthe art to result in compounds of Formula III. The method used in thedeprotection depends on the type of protecting group. A description ofsuch protecting groups and methods for deprotecting them may be foundin: Protective Groups in Organic Synthesis, Second Edition, T. W. Greenand P. G. M. Wuts, John Wiley and Sons, New York, 1991. When a methyl orethyl ester is used, an aqueous sodium hydroxide solution in ethanol ordimethoxyethane is conveniently employed for its removal.

If not commercially available, nitrile IV can be prepared substantiallyas described below in Scheme B depicting the formation of 3-acetonitrilesubstituted indoles of Formula IV where Z is a bond. Thus, an indolemoiety in a weak acid solution, for example, acetic acid in ethanol, istreated with aqueous formaldehyde and dimethyl amine in an alcoholsolvent. The 3-(dimethylamino)methyl indole product can then be treatedwith sodium or potassium cyanide in N,N-dimethylformamide at elevatedtemperatures to provide the 3-acetonitrile substituted indoleintermediate. Alternatively, an iminium salt likeN,N-dimethylmethyleneammonium chloride can be used to prepare the3-(dimethylamino)methyl indole intermediate.

The 3-(dimethylamino)methyl indole intermediate can also be converted tothe 3-acetonitrile substituted indole intermediate via the trimethylammonium salt. The salt can be prepared by treating the gramineintermediate with an alkalating agent like methyl iodide. The trimethylammonium salt intermediate can then be converted to the nitrile bytreatment with sodium or potassium cyanide in a solvent likeN,N-dimethylformamide. In general, the conversion to the acetonitrileoccurs under more mild conditions when the trimethyl ammonium salt isused.

Alternatively, other compounds, such as those where Z—Ar represents awide variety of substituted heterocycles, may be prepared using thegeneral method outlined in Scheme C. Here, substituted indoleintermediates where X is an activating group like hydroxyl, halogen,dialkyl amino, trialkyl ammonium or benzotriazole are coupled withQ-Z—Ar groups using methods well-established in indole chemistry.Examples of these methods where Q is Na or H and Z is sulfur, oxygen,nitrogen carbon or a bond are described in (A) Tidwell, J. H.; Peat, A.J.; Buchwald, S. L. J. Org. Chem. 1994, 59, 7164; (B) Bruneau, P.;Delvare, C.; Edwards, M. P.; McMillan, R. M. J. Med. Chem. 1991, 34,1028; (C) Gan, T.; Cook, J. M. Tetrahedron Lett. 1997, 38, 1301; (D)Cerreto, F.; Villa, A.; Retico, A.; Scalzo, M. Eur. J. Med. Chem. 1992,27 701; (E) Majchrzak, M. W.; Zobel, J. N.; Obradovich, D. J.; Synth.Commun. 1997, 27, 3201; (F) DeLeon, C. Y.; Ganem, B. J. Org. Chem. 1996,61, 8730; (G) Katritzky, A. R.; Toader, D; Xie, L. J. Org. Chem. 1996,61, 7571.

It is understood that, depending on the specific chemistry used, aprotecting group, P, may be required. In general, P represents groupssuch as acyloxy, alkyl, sulfonyl or A-COOR. The use of these generalmethods is illustrated in Protective Groups in Organic Synthesis, SecondEdition, T. W. Green and P. G. M. Wuts, John Wiley and Sons, New York,1991.

In general, the intermediate compounds wherein R₂₋₆ is aryl orheteroaryl can be synthesized by the chemistry illustrated in reactionScheme D below. For example, treatment of the potassium salt of anoptionally substituted bromoindole with tert-butyllithium at lowtemperature in an ethereal solvent such as ether or tetrahydrofuranfollowed by the addition of an electrophile represents a general methodfor obtaining substituted indoles, as described by Rapoport, H. (J. Org.Chem. 1986, 51, 5106). For a discussion of a synthesis where R is acyl,see Biorg. Med. Chem. Lett. 1999, 9, 333; where R is, thiomethyl, seeHeterocycles, 1992, 34, 1169; and where R is cycloalkyl, see J. Med.Chem. 1999, 42, 526.

More specifically the addition of a trialkyl borate followed by anacidic work-up provides the desired indole boronic acids (Heterocycles,1992, 34, 1169). Indole boronic acids can be used in well establishedtransition metal catalyzed coupling reactions like the Suzuki reactionto provide aryl and heteroaryl indoles. These reactions are most oftencarried out in a mixture of ethereal or alcohol solvents with aqueousbase in the presence of palladium catalyst, such as Pd(OAc)₂, Pd(OAc)₂w/PPh₃ or Pd(PPh₃)₄ as described in Tetrahedron Lett. 1998, 39, 4467, J.Org. Chem. 1999, 64, 1372 and Heterocycles 1992, 34, 1395.

Alternatively, an optionally substituted bromoindole can be treated withan arylboronic acid and a palladium catalyst to provide arylindoles inlarge quantities (Synlett 1994, 93). A general review of Suzukicross-couplings between boronic acids and aryl halides can be found inMiyaura, N; Suzuki, A. Chem. Rev. 1995, 95, 2457.

For example, treatment of the advanced intermediate indole X with anaryl or heteroaryl boronic acid using Pd-mediated coupling conditionsprovides the desired aryl and heteroaryl indole product XI as shown inscheme (E). In general the utility of this method is determined by theease of synthesis of advanced intermediates of type X and the commercialavailability of aryl and heteroaryl boronic acids.

In addition, certain organometallic reactions eliminate the need for denovo construction of the indole nucleus. For example, the Stillereaction serves as a general method for the synthesis of regiocontrolledsubstitution of indole intermediates as described by Farina, V.;Krishnamurthy, V; Scott, W., Organic Reactions, 1998, 50, 1-652. Asindicated in the scheme below, the indole may serve as the organotinspecies or the aryl halide. The stannylindole (XII), where P is asuitable protecting group such as [2-(trimethyl)ethoxy]methyl (SEM) oran alkyl substituent, is treated with a variety of partners (i.e.,vinyl/allylic halides, vinyl triflates, aryl/heteroaryl halides and acylhalides) in the presence of a Pd(0)L_(n) catalyst to provide the desiredindoles (XII) (Synnlett 1993, 771, Helv. Chim. Acta 1993, 76, 2356 andJ. Org. Chem. 1994, 59, 4250). Conversely, a haloindole (XIV) is treatedwith a variety of tin reagents under Stille conditions to provide thedesired substituted indoles (XV) as described in Heterocycles 1988, 27,1585 and Synth. Comm 1992, 22, 1627).

A general procedure for the synthesis of intermediate compounds usingamines of the formula NR_(x)R_(X2) (NR₁R₂ in the scheme below) is givenin scheme F below. In Scheme F, R_(x) and R_(x2) are the same ordifferent and represent hydrogen, C₁-C₆ alkyl, or R_(x) and R_(x2)together represent a group of the formula:

where J and each r is as defined above for formula I.

As shown in Scheme F, nucleophilic substitution of X (X is halogen,preferably fluorine) in an aromatic system is a method often used tosubstitute aromatic rings with amine and ether functionalities. Both 4-and 5-fluoro-2-nitrotoluene are sufficiently activated to undergosubstitution with amines in the presence of K₂CO₃ in a polar aproticsolvent such as, for example, DMSO as described in J. Med. Chem. 1993,36, 2716. The Leimgruber-Batcho two-step method is a general process forthe construction of the indole ring system from the appropriateo-nitrotoluene. This reaction involves the condensation of ano-nitrotoluene with N,N-dimethylformamide dimethyl acetal followed by areductive cyclization under suitable conditions such as hydrogen over apalladium catalyst or Zn/HOAc as described in Sundberg, R. J. Indoles;Chapter 2, Academic Press Inc., San Diego, Calif., 1996. Arepresentative description of the process can also be found in OrganicSynthesis, 1984, 63, 214.

A general procedure for the synthesis of intermediate compounds whereinR is an aromatic, heteroaromatic or alkyl group is indicated in Scheme Gbelow. As previously described, nucleophilic substitution of halogen,preferably fluorine, in an aromatic system is a method often used tosubstitute aromatic rings with amine and ether functionalities. Both 4-and 5-fluoro-2-nitrotoluene are sufficiently activated enough to undergosubstitution with alcohols or phenols in the presence of K₂CO₃ in apolar aprotic solvent such as DMSO. A similar system using KOH andphenol is described in J. Med. Chem. 1994, 37, 1955. Alternatively,solid-liquid phase transfer catalysis (PTC) methods have been used toprepare intermediate ethers of this type as described in Synth. Comm.1990, 20, 2855. The appropriately substituted o-nitrotoluene can then beconverted to the appropriate indole by the Leimgruber-Batcho methodpreviously described.

The preparation of intermediate alkoxy indole compounds wherein R isC₁-C₆ alkyl is outlined in Scheme H below. Commercially availablenitrophenols can be alkylated under mild conditions with a base such as,for example, K₂CO₃ or Cs₂CO₃, in a polar aprotic solvent, e.g. CH₃CN,with a variety of suitable alkyl halides. See Synth. Comm. 1995, 25,1367. The alkoxy o-nitrotoluene can then be converted to the desiredindole as described above.

Alternatively, some examples of the invention where Z is a bond and Aris a substituted heterocycle such as a thiazole; or Z is amide and Ar isa substituted phenyl can be conveniently prepared from an indole3-acetic acid derivative as illustrated in Scheme I. Using this method,the carboxylic acid moiety is activated and coupled with an aryl amine.Some examples of activating methods well-known to those skilled in theart include formation of acid chloride, mixed anhydrides and couplingreagents such as 1,3-dicyclohexylcarbodiinide (DCC). A review of suchmethod can be found in Bodanszky, M. Principles of Peptide Synthesis;Springer-Verlag: New York, 1984. For the examples where Z is a bond andAr is a substituted benzothiazole or benzoxazole, the intermediate amideor thioamide can be cyclized into the aromatic ring. Examples of thesetypes of heterocycle forming reactions are described in Mylar, B. L. etal. J. Med. Chem. 1991, 34, 108. In addition, the carboxylic acid can beconverted to a chloro- or bromomethyl ketone and condensed withnucleophiles like thioamides or 2-aminothiophenols to produce thiazoleor benzothiazine derivatives. Examples of methods to prepare the chloro-and bromomethyl ketones are illustrated in Rotella, D. P.; TetrahedronLett. 1995, 36, 5453 and Albeck, A.; Persky, R.; Tetrahedron 1994, 50,6333. Depending on the reaction conditions in a given synthetic sequencea protecting group may be required. It is also understood that thespecific order of steps used in the synthesis depends on the particularexample being prepared. P may represent H, A-COOH, A-COO-lower alkyl ora simple protecting group that can be removed at a late stage of thesynthesis. When such a protecting group is used, the A-CO2R6 group canbe introduced near the end of the synthesis after the Z—Ar group hasbeen assembled. Method of introducing the Z—Ar group are similar tothose already described.

Another strategy involves the synthesis of substituted indoles via anintramolecular cyclization of an aniline nitrogen onto a substitutedalkyne as shown in Scheme J. Typical approaches utilize commerciallyavailable o-iodoaniline derivatives. When these intermediates areunavailable, the regioselective ortho iodination of aromatic amines isused to generate the required intermediate (J. Org. Chem. 1996, 61,5804). For example, Iodophenyl intermediates are treated withtrimethylsilylacetylene in the presence of a Pd catalyst and a Cu(I)source, such as cupric iodide, to produce o-alkynylanilines. SeeHeterocycles, 1996, 43, 2471 and J. Org. Chem. 1997, 62, 6507. Furtherelaboration of the o-alkynylaniline to the desired indole can be done bya copper-mediated cyclization or a base-induced amine ring closure ontothe alkyne functionality (J. Med. Chem. 1996, 39, 892). Alternativemodifications have been made in the acetylenic derivatives to generatemore elaborate indole structures as described in J. Am. Chem. Soc. 1991,113, 6689, Tetrahedron Lett. 1993, 24, 2823 and Tetrahedron Lett. 1993,34, 6471.

Those having skill in the art will recognize that the starting materialsmay be varied and additional steps employed to produce compoundsencompassed by the present invention, as demonstrated by the followingexamples. In some cases, protection of certain reactive functionalitiesmay be necessary to achieve some of the above transformations. Ingeneral, the need for such protecting groups will be apparent to thoseskilled in the art of organic synthesis as well as the conditionsnecessary to attach and remove such groups.

The disclosures in this application of all articles and references,including patents, are incorporated herein by reference.

The preparation of the compounds of the present invention is illustratedfurther by the following examples, which are not to be construed aslimiting the invention in scope or spirit to the specific procedures andcompounds described in them.

Example 1 Preparation of2-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

2-Methyl-3-(4,5,7-Trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acidwas prepared in a manner analogous to that set forth in Example 2,except 2-methylindole was used instead of 5-chloroindole in step 1:178-180° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.75-7.62 (m, 1H), 7.45 (d,J=9.0 Hz, 1H), 7.39 (d, J=9.0 Hz, 1H), 7.08 (t, J=9 Hz, 1H), 6.99 (t,J=9.0 Hz, 1H), 5.00 (s, 2H), 4.60 (s, 2H), 2.38 (s, 3H); LRMS calcd forC₁₉H₁₃F₃N₂O₂S: 390.0. found 391.0 (M+1)⁺. Anal. Calcd for C₁₉H₁₃F₃N₂O₂S:C, 58.46; H, 3.36; N, 7.18; S, 8.21. Found: C, 58.47; H, 3.29; N, 7.12,S, 8.18.

Example 2 Preparation of5-chloro-3-(4,5,7-Trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acid

5-chloroindole-3-acetonitrile

A solution of aqueous formaldehyde (37%, 2.95 mL, 66.0 mmol) anddimethylamine (40%, 5.30 mL, 66.0 mmol) in 20 mL EtOH was cooled to 0°C. 5-Chloroindole (4.0 g, 26.4 mmol) was dissolved in a HOAc:EtOHmixture (1:1, 40 mL) and added dropwise to the reaction mixture. Afterstirring at this temperature for 2 h, the mixture was allowed to warm toroom temperature and stir overnight. The mixture was added to a sat'dsolution of NaHCO₃. 1 N NaOH was added until the pH was between 9-10.The resulting mixture was extracted with CH₂Cl₂ (3×). The organics werecombined and washed with a sat'd aq. NaCl, dried over MgSO₄, filteredand concentrated in vacuo to give 4.65 g (85%) of5-chloro-3-[(dimethylamino)methyl]indole as a yellow powder. Withoutfurther purification, 5-chloro-3-[(dimethylamino)methyl]indole (4.65 g,22.4 mmol) was dissolved in dimethylformamide (80 mL) at roomtemperature with stirring. To this was added KCN (2.18 g, 33.5 mmol) inH₂O (10 mL). The mixture was warmed to 140° C. and stirred for 14 h. H₂Owas added and the mixture was extracted with EtOAc (2×). The organicswere combined and washed with sat'd brine, dried over MgSO₄, filteredand concentrated in vacuo. The residue was purified by SiO₂ flashchromatography (3:2, Heptane: EtOAc) to give 2.65 g (63%) of5-chloroindole-3-acetonitrile. ¹H NMR (DMSO-d₆, 300 MHz) δ 11.30 (br s,1H), 7.63 (s, 1H), 7.42-7.38 (m, 2H), 7.05 (d, J=6.0 Hz, 1H), 5.70 (s,2H),

5-chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

5-chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acidwas prepared in a manner analogous to that set forth in Example 3 (steps1-7), except 5-chloroindole-3-acetonitrile was used instead of 3-indolylacetonitrile in step 5: mp 188-189° C.; ¹H NMR (DMSO-d₆, 300 MHz)7.73-7.68 (m, 1H), 7.63 (d, J=1.8 Hz, 1H), 7.51 (s, 1H), 7.45 (d, J=9.0Hz, 1H), 7.14 (dd, J₁=9.0, J₂=2.4 Hz, 1H), 5.04 (s, 2H), 4.65 (s, 2H);LRMS calcd for C₁₈H₁₀F₃N₂O₂SCl: 410.0. found 411.0 (M+1)⁺. Anal. Calcdfor C₁₈H₁₀F₃N₂O₂SCl: C, 52.63; H, 2.45; N, 6.82; S, 7.81. Found: C,52.56; H, 2.40; N, 6.71, S, 7.72.

Example 3 Preparation of3-(4,5,7-Trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acid

2,3,5,6-Tetrafluoroacetanilide

A solution of 2,3,5,6-tetrofluoroaniline (200 g, 1.21 mol) in anhydrouspyridine (103 mL, 1.27 mol) was treated with acetic anhydride (120 mL,1.27 mol) and heated to 120° C. for 2 h. After cooling to roomtemperature, the solution was poured into ice-cold water (500 mL). Theresulting precipitate was filtered, dissolved in ethyl acetate, driedover MgSO₄, filtered and concentrated. The solid material was washedwith heptane (200 mL) and dried to give 2,3,5,6-tetrafluoroacetanilideas a white crystalline solid (206 g, 82%): mp 136-137° C.; R_(f) 0.48(50% ethyl acetate in heptane); ¹H NMR (DMSO-d₆, 300 MHz) δ 10.10 (s, 1H), 7.87-7.74 (m, 1H), 2.09 (s, 3H). Anal. Calcd for C₈H₅F₄NO: C, 46.39;H, 2.43; N, 6.67. Found C, 46.35; H, 2.39; N, 6.68.

2,3,5,6-Tetrafluorothioacetanilide

A flame-dried, 4-necked 5,000 mL round-bottomed flask was charged withphosphorous pentasulfide (198 g, 0.45 mol) and diluted with anhydrousbenzene (3,000 mL, 0.34 M). 2,3,5,6-tetrafluoroacetanilide (185 g, 0.89mol) was added in one portion and the bright yellow suspension washeated to a gentle reflux for 3 h. The solution was cooled to 0° C. andfiltered. The insoluble material was washed with ether (2×250 mL) andthe combined filtrate was extracted with 10% aq. NaOH (750 mL, 500 mL).After cooling the aqueous layer to 0° C., it was carefully acidifiedwith conc. HCl (pH 2-3). The precipitated product was collected byfiltration and washed with water (500 mL). The yellow-orange materialwas dissolved in ethyl acetate (1,000 mL), dried over MgSO₄ andactivated charcoal (3 g), filtered through a short pad of silica (50 g),and concentrated. The resulting solid was triturated with heptane (500mL) and filtered to give 2,3,5,6-tetrafluorothioacetanilide (174.9 g,88%): mp: 103-104° C.; R_(f) 0.67 (50% ethyl acetate in heptane); ¹H NMR(DMSO-d₆, 300 MHz) δ 11.20 (s, 1H), 8.00-7.88 (m, 1H), 2.66 (s, 3H).Anal. Calcd for C₈H₅F₄NS: C, 43.05; H, 2.26; N, 6.28. Found C, 43.10; H,2.23; N, 6.19.

4,5,7-Trifluoro-2-methylbenzothiazole

A flame-dried 5,000 mL round-bottomed flask equipped with over-headstirrer was charged with sodium hydride (15.9 g, 0.66 mol) and dilutedwith anhydrous toluene (3,000 mL, 0.2 M). The suspension was cooled to0° C., and treated with 2,3,5,6-tetrafluorothioacetanilide (134 g, 0.60mol) in one portion. The solution was warmed to room temperature over 1h, then heated to a gentle reflux. After 30 min, dimethylformamide (400mL) was carefully added and the mixture was stirred for an additional 2h. The solution was cooled to 0° C. and added to ice-water (2,000 mL).The solution was extracted with ethyl acetate (1,500 mL) and washed withsat'd. aq. NaCl (1,000 mL). The organic layer was concentrated todryness, diluted with heptane and successively washed with water (300mL) and sat'd. aq. NaCl (1,000 mL). The organic layer was dried overMgSO₄, filtered and concentrated to give4,5,7-trifluoro-2-methylbenzothiazole (116.8 g, 96%) as a light brownsolid: mp: 91-92° C.; R_(f) 0.56 (30% ethyl acetate in heptane); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.76-7.67 (m, 1H), 2.87 (s, 3H); Anal. Calcd forC₈H₄F₃NS: C, 47.29; H, 1.98; N, 6.82; S, 15.78. Found C, 47.56; H, 2.07;N, 6.82; S, 15.59.

2-Amino-3,4,6-trifluorothiophenol Hydrochloride

A solution of 4,5,7-trifluoro-2-methylbenzothiazole (25.0 g, 123 mmol)in ethylene glycol (310 mL, 0.4 M) and 30% aq. NaOH (310 mL, 0.4 M) wasdegassed using a nitrogen stream then heated to a gentle reflux (125°C.) for 3 h. The solution was cooled to 0° C. and acidified to pH 3-4using conc. HCl (appox. 200 mL). The solution was extracted with ether(750 mL) and washed with water (200 mL). The organic layer was driedover Na₂SO₄, filtered and treated with 2,2-di-tert-butyl-4-methylphenol(0.135 g, 0.5 mol %). After concentrating to dryness, the crude productwas dissolved in anhydrous methanol (200 mL) and treated with an HClsolution in 1,4-dioxane (37 mL, 4 N, 148 mmol). The resulting mixturewas concentrated to dryness, triturated with isopropylether (100 mL) andfiltered to give 2-amino-3,4,6-trifluorothiophenol hydrochloride (19.3g, 73%) as a light brown solid that was used without furtherpurification. mp. 121-124 C; R_(f) 0.43 (30% ethyl acetate in heptane);Anal. Calcd for C₆H₅ClF₃NS: C, 33.42; H, 2.34; N, 6.50; S, 14.87. FoundC, 33.45; H, 2.27; N, 6.48; S, 14.96.

3-cyanomethyl-indole-N-acetic acid, Ethyl Ester

Under an atmosphere of nitrogen, a solution of 3-indolyl acetonitrile(25.0 g, 160 mmol) in dry acetonitrile (530 mL, 0.3 M) was treated withsodium hydride (95%, 4.2 g, 168 mmol) and stirred for 30 min. Ethylbromoacetate (21.3 mL, 192 mmol) was added in a dropwise manner over 10min and the solution was stirred at room temperature for 16 h. Afterconcentrating under reduced pressure, the resulting residue wasdissolved in ethyl acetate and washed with sat'd. aq. NaCl. The organicextracts were dried over MgSO₄, filtered and concentrated. The crudeproduct was recrystallized from heptane and ethyl acetate to give thetarget compound as a white crystalline solid (19 g, 49%): mp 98-99° C.;R_(f) 0.29 (30% ethyl acetate in heptane); ¹H NMR (DMSO-d₆, 300 MHz) δ7.59 (dd, J₁=7.8 Hz, J₂=0.6 Hz, 1H), 7.40 (dd, J₁=8.1 Hz, J₂=0.6 Hz,1H), 7.36 (s, 1H), 7.18 (b t, J=7.2 Hz, 1H), 7.10 (b t, J=7.2 Hz, 1H),5.12 (s, 2H), 4.14 (q, J=7.2 Hz, 2H), 4.06, (s, 2H), 1.20 (t, J=7.2 Hz,3H);); LRMS calcd for C₁₄H₁₄N₂O₂: 242.3. found 243.0 (M+1)⁺. Anal. Calcdfor C₁₄H₁₄N₂O₂: C, 69.49; H, 5.82; N, 11.56. Found C, 69.39; H, 5.89; N,11.59.

3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid, EthylEster

Under a nitrogen atmosphere, a solution of3-acetonitrile-indole-N-acetic acid, ethyl ester (11.0 g, 45.4 mmol) inanhydrous ethanol (90 mL, 0.5 M) was treated with2-amino-3,4,6-trifluorothiophenol hydrochloride (12.7 g, 59.0 mmol) andheated to a gentle reflux for 16 h. After cooling to room temperature,the solution was concentrated under reduced pressure, diluted with ethylacetate and washed with 2N HCl and sat'd. aq. NaCl. The organic layerwas dried over MgSO₄, filtered and concentrated. Purification by MPLC(10-50% ethyl acetate in heptane, 23 mL/min, 150 min) to give3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid, ethylester (6.0 g, 36%) as a white crystalline solid: mp 110-111° C.; R_(f)0.41 (30% ethyl acetate in heptane); ¹H NMR (DMSO-d₆, 300 MHz) δ7.74-7.66 (m, 1H), 7.54 (d, J=7.8 Hz, 1H), 7.46 (s, 1H), 7.40 (d, J=8.1Hz, 1H), 7.15 (br t, J=6.9 Hz, 1H), 7.04 (br t, J=7.8 Hz, 1H), 5.14, s,2H), 4.66 (s, 2H), 4.14 (q, J=7.2 Hz, 3H); LRMS calcd for C₂₀H₁₅F₃N₂O₂S:404.4. found 405.0 (M+1)⁺. Anal. Calcd for C₂₀H₁₅F₃N₂O₂S; C, 59.40; H,3.74; N, 6.93; S, 7.93. Found C, 59.52; H, 3.721; N, 6.92; S, 8.04.

3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

A solution of give3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid, ethylester (5.91 g, 14.6 mmol) in 1,2-dimethoxyethane (73 mL, 0.2 M) wascooled to 0° C. and treated with aq. NaOH (1.25 N, 58 mL, 73.1 mmol) ina dropwise manner over 15 min. After the addition was complete, thesolution was stirred for an additional 30 min, acidified to pH 3 with 2NHCl, and concentrated under reduced pressure. The residue was dissolvedin ethyl acetate (200 mL) and washed with sat'd. aq. NaCl (30 mL). Theorganic extract was dried over Na₂SO₄, filtered and concentrated. Theresulting material was stirred as a suspension in heptane, filtered anddried to give 3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid (5.38 g, 98%) as a pale yellow solid: mp 177-178° C.; R_(f) 0.44(20% methanol in dichloromethane); ¹H NMR (DMSO-d₆, 300 MHz) δ 7.74-7.65(m, 1H), 7.53 (d, J=7.5 Hz, 1H), 7.46 (s, 1H), 7.40 (d, J=8.1 Hz, 1H),7.15 (b t, J=6.9 Hz, 1H), 7.03 (b t, J=7.2 Hz, 1H), 5.03 (s, 2H), 4.65(s, 2H); LRMS calcd for C₁₈H₁₁F₃N₂O₂S: 376.4. found 375.0 (M−1)⁻. Anal.Calcd for C₁₈H₁₁F₃N₂O₂S: C, 57.44; H, 2.95; N, 7.44; S, 8.52. Found C,57.58; H, 2.99; N, 7.38; S, 8.51.

Example 4 Preparation of5-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

5-Methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acidwas prepared in a manner analogous to that set forth in Example 2,except 5-methylindole was used instead of 5-chloroindole in step 1: mp131-133° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.73-7.62 (m, 1H), 7.39 (s,1H), 7.30 (s, 1H), 7.27 (d, J=9.0 Hz, 1H), 6.96 (dd, J₁=9.0 Hz, J₂=2.4Hz, 1H), 4.98 (s, 2H), 4.60 (s, 2H), 2.32 (s, 3H); LRMS calcd forC₁₉H₁₃F₃N₂O₂S: 390.0. found 391.0 (M+1)⁺. Anal. Calcd for C₁₉H₁₃F₃N₂O₂S:C, 58.46; H, 3.36; N, 7.18; S, 8.21. Found: C, 58.36; H, 3.30; N, 7.10,S, 8.20.

Example 5 Preparation of7-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

7-Methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acidwas prepared in a manner analogous to that set forth in Example 2,except 7-methylindole was used instead of 5-chloroindole in step 1: mp216-218° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.73-7.63 (m, 1H), 7.36-7.32(m, 2H), 6.92-6.88 (m, 2H), 5.17 (s, 2H), 4.60 (s, 2H), 2.55 (s, 3H);LRMS calcd for C₁₉H₁₃F₃N₂O₂S: 390.0. found 391.0 (M+1)⁺. Anal. Calcd forC₁₉H₁₃F₃N₂O₂S: C, 58.46; H, 3.36; N, 7.18; S, 8.21. Found: C, 58.37; H,3.37; N, 7.11; S, 8.13.

Example 6 Preparation of6-chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

6-Chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acidwas prepared in a manner analogous to that set forth in Example 2,except 6-chlorolindole was used instead of 5-chloroindole in step 1: mp194-195° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.73-7.63 (m, 1H), 7.50 (d,J=8.4 Hz, 1H), 7.46-7.42 (m, 2H), 7.00 (dd, J₁=8.4 Hz, J₂=2.1 Hz, 1H),4.76 (s, 2H), 4.62 (s, 2H); LRMS calcd for C₁₈H₁₀F₃N₂O₂SCl: 410.0. found411.0 (M+1)⁺. Analysis calculated for C₁₈H₁₀F₃N₂O₂SCl: C, 52.63; H,2.45; N, 6.82; S, 7.81. Found: C, 52.50; H, 2.44; N, 6.74, S, 7.69.

Example 7 Preparation of5-benzyloxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid

5-Benzyloxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticAcid was prepared in a manner analogous to that set forth in Example 2,except 5-benzyloxyindole was used instead of 5-chloroindole in step 1:mp 165-168° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.73-7.65 (m, 1H) 7.40-7.30(m, 3H), 7.28-7.10 (m, 4H), 7.10 (d, J=2.4 Hz, 1H), 6.87-6.80 (m, 1H),5.05 (s, 2H), 4.95 (s, 2H), 4.57 (s 2H); LRMS calcd for C₂₅H₁₇F₃N₂O₂S:482.0. found 483.0 (M+1)⁺.

Example 8 Preparation of6-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

6-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acidwas prepared in a manner analogous to that set forth in Example 2,except 6-fluoroindole was used instead of 5-chloroindole in step 1: mp200-203° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.73-7.65 (m, 1H), 7.53 (dd,J₁=8.4 Hz, J₂=3.3 Hz, 1H), 7.44 (s, 1H), 7.34 (dd, J₁=10.5 Hz, J₂=2.4Hz, 1H), 6.93-6.68 (m, 1H), 5.11 (s, 2H), 4.64 (s, 2H); LRMS calcd forC₁₈H₁₀F₄N₂O₂S: 394.0. found 395 (M+1).

Example 9 Preparation of5-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

5-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acidwas prepared in a manner analogous to that set forth in Example 2,except 5-fluoroindole was used instead of 5-chloroindole in step 1: mp193-195° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.65 (m, 1H), 7.51 (s, 1H),7.42 (br dd, J₁=9.0 Hz, J₂=4.8 Hz, 1H), 7.34 (br dd, J₁=9.9 Hz, J₂=2.4Hz, 1H), 7.02-6.96 (m, 1H), 5.03 (s, 2H), 4.62 (s, 2H); LRMS calcd forC₁₈H₁₀F₄N₂O₂S: 394.0. found 395 (M+1).

Example 10 Preparation of6-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

6-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic Acidwas prepared in a manner analogous to that set forth in Example 2,except 6-methylindole was used instead of 5-chloroindole in step 1: mp211-213° C., R_(f)0.50 (10% methanol in diehloromethane); ¹H NMR(DMSO-d₆, 300 MHz) 7.72-7.63 m, 1H), 7.37 (d, J=7.1 Hz, 1H), 7.35 (s,1H), 7.18 (s, 1H), 6.85 (d, J=8.4 Hz, 1H), 5.08 (s, 2H), 4.60 (s, 2H),2.37 (s, 3H).

Example 11 Preparation of3-(5-trifluoromethylbenzothiazol-2-yl)methyl-indole-N-acetic Acid

3-(5-trifluoromethylbenzothiazol-2-yl)methyl-indole-N-acetic Acid wasprepared in a manner analogous to that set forth in Example 3 (steps5-7), except 2-amino-4-(trifluoromethyl)-benzenethiol hydrochloride wasused instead of 2-amino-3,4,6-trifluorothiophenol hydrochloride in step6: mp 233-234° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 8.29 (s, 1H), 8.19 (br d,J=8.1 Hz, 1 H), 7.68 (br d, J=9.0 Hz, 1H), 7.49 (br d, J=6.9 Hz, 1H),7.41 (s, 1H), 7.38 (br d, J=8.4 Hz, 1H), 7.12 (br t, J=6.9 Hz, 1H), 7.00(br t, J=6.9 Hz, 1H), 5.01 (s, 2H), 4.60 (s, 2H).

Example 12 Preparation of5-Methyl-3-(5-Trifluoromethylbenzothiazol-2-yl)methyl-indole-N-aceticacid

5-Methyl-3-(5-trifluoromethylbenzothiazol-2-yl)methyl-indole-N-aceticacid was prepared in a manner analogous to that set forth in Example 2,except 5-methylindole was used instead of 5-chloroindole in step 1 and,2-amino-4-(trifluoromethyl)-benzenethiol hydrochloride was used insteadof 2-amino-3,4,6-trifluorothiophenol hydrochloride in step 2 (Example 3,step 6): mp 248-249° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 8.27 (s, 1H), 8.20(d, J=8.4 Hz, 1H), 7.68 (d, J=8.4 Hz, 1H), 7.35 (s, 1H), 7.27 (s, 1H),7.25 (d, J=8.1 Hz, 1H), 6.95 (d, J=8.1 Hz, 1H), 4.96 (s, 2H), 4.57 (s,2H), 2.31, (s, 3H); LRMS calcd for C₂₀H₁₅F₃N₂O₂S. found 405 (M+H).

Example 13 Preparation of 3-(3-nitrophenyl)methyl-indole-N-acetic acid

Preparation of indole-N-acetic acid, ethyl ester

Under an atmosphere of nitrogen, a solution of indole (15.0 g, 128 mmol)in dry acetonitrile (300 mL, 0.4 M) was treated with sodium hydride(95%, 3.69 g, 153 mmol) and stirred for 30 min. Ethyl bromoacetate (17.0mL, 153 mmol) was added in a dropwise manner over 10 min and thesolution was stirred at room temperature for 16 h. After concentratingunder reduced pressure, the resulting residue was dissolved in ethylacetate and washed with sat'd. aq. NaCl. The organic extracts were driedover MgSO₄, filtered and concentrated. The crude product was purified byflash column chromatography (50% ethyl acetate in heptane): Rf0.25 (40%ethyl acetate in heptane) ¹H NMR (DMSO-d₆, 300 MHz) δ 7.53 (d, J=6.3 Hz,1H), 7.38-7.31 (m, 2H), 7.11 (br t, J=7.2 Hz, 1H), 7.02 (br t, J=7.2 Hz,1H), 6.45-6.43 (m, 1H), 5.10 (s, 2H), 4.12 (q, J=7.2 Hz, 2H), 1.19 (t,J=7.2 Hz, 3H).

Preparation of 3-(3-nitrophenyl)methyl-indole-N-acetic acid, ethyl ester

Indole-N-acetic acid, ethyl ester (0.500 g, 2.50 mmol) was dissolved in1,4-dioxane (5 mL) at room temperature with stirring. To this solutionwas added Ag₂CO₃/Celite (50% by weight, 0.500 g, 0.9 mmol). The mixturewas warmed to 90° C. and maintained overnight. H₂O was added to thereaction mixture followed by extracted with EtOAc (2×). The organicswere combined and washed with a sat'd brine solution, dried over MgSO₄,filtered and concentrated in vacuo. The residue was purified by SiO₂flash chromatography (3:2 Heptane:EtOAc) to give 180 mg (22%) as a paleyellow oil. ¹H NMR (DMSO-d₆, 300 MHz) δ 8.10 (s, 1H), 8.02 (d, J=8.1 Hz,1H), 7.75 (d, J=7.2 Hz, 1H), 7.59-7.57 (m, 1H), 7.46-7.39 (m, 1H), 7.33(d, J=8.1 Hz, 1H), 7.20 (s, 1H), 7.13-6.89 (m, 2H), 5.06 (s, 2H), 4.19(s, 2H), 4.13 (q, J=7.2 Hz, 2H), 1.18 (t, J=7.2 Hz, 3H).

Preparation of 3-(3-nitrophenyl)methyl-indole-N-acetic Acid

3-(3-Nitrophenyl)methyl-indole-N-acetic Acid, ethyl ester (0.175 g, 0.5mmol) was dissolved in THF:EtOH (1:4, 5 mL) at room temperature withstirring. The mixture was cooled to 0° C. and treated with 1N NaOH (1.55mL, 1.6 mmol). The mixture was allowed to stir at this temperature for 2h. 1 N HCl was added and the mixture extracted with EtOAc (2×). Theorganics were combined and washed with a sat'd brine solution, driedover MgSO₄, filtered and concentrated in vacuo. The residue wastriturated with heptane and vacuum-filtered with several heptanewashings to give 110 mg (69%) the desired compound as an off-whitepowder. mp 163-165° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 8.11 (s, 1H), 8.03(d, J=8.1 Hz, 1H), 7.75 (d, J=8.1 Hz, 1H), 7.53 (t, J=8.1 Hz, 1 H), 7.45(d, J=8.1 Hz, 1H), 7.33 (d, J=8.4 Hz, 1H), 7.20 (s, 1H), 7.11 (t, J=7.2Hz, 1H), 6.97 (t, J=7.2 Hz, 1H), 4.96 (s, 2H), 4.18 (s, 2H); LRMS calcdfor C₁₇H₁₄N₂O₄S: 310.0. found 311 (M+1)⁺.

Example 14 Preparation of2-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

2-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acidwas prepared in a manner analogous to that set forth in Example 2,except that 2-phenylindole was used instead of 5-chloroindole in step 1:mp 238-239° C.; R_(f) 0.60 (10% methanol in chloroform); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.60-7.70 (m, 1H), 7.39-7.58 (m, 7H), 7.20 (t, J=9Hz, 1H), 7.07 (t, J=9 Hz, 1H), 4.80 (s, 2H), 4.45 (s, 2H); LRMS calcdfor C₂₄H₁₅F₃N₂O₂S: 452.0. found 453.0 (M+1)⁺. Anal. Calcd forC₂₄H₁₆F₃N₂O₂S: C, 63.71; H, 3.34; N, 6.19; S, 7.09. Found: C, 63.46; H,3.32; N, 6.11; S, 6.96.

Example 15 Preparation of5-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid3-cyanomethyl-5-phenyl-indole-N-acetic acid, ethyl ester

5-Bromo-3-cyanomethyl-indole-N-acetic acid, ethyl ester (1.0 g, 3.1mmol) and phenylboronic acid (0.418 g, 3.4 mmol) were dissolved inanhydrous DME at room temperature under a nitrogen atmsophere andtreated with Pd(OAc)₂ (2.1 mg, 0.0093 mmol) and PPh₃ (7.4 mg, 0.028mmol). This mixture was heated to reflux and 2 M Na₂CO₃ (3.11 mL, 6.2mmol) was added via syringe. After 12 h, the mixture was cooled to roomtemperature and added to H₂O (50 mL). The resultant mixture wasextracted with EtOAc (2×, 100 mL) and the organics were combined andwashed with a sat'd aqueous NaCl solution, dried over MgSO₄, filteredand concentrated in vacuo. The residue was purified by SiO₂ flashchromatography (heptane to 1:1 heptane/EtOAc) to give the desiredmaterial as a white solid (445 mg, 45%); ¹H NMR (DMSO-d₆, 300 MHz) δ7.64-7.74 (m, 4H), 7.39-7.44 (m, 4H), 7.29-7.34 (m, 1H), 5.20 (s, 2H),4.15 (q, J=7.2 Hz, 2H), 4.08 (s, 2H), 1.20 (t, J=7.2 Hz, 3H).

5-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl indole-N-acetic acid

5-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acidwas prepared in a manner analogous to that set forth in Example 2,except that 5-phenylindole was used instead of 5-chloroindole in step 1:mp 156-159° C.; R_(f) 0.55 (10% methanol in chloroform); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.66-7.69 (m, 4H), 7.57-7.60 (m, 1H), 7.39-7.47 (m,3H), 7.29-7.35 (m, 2H), 5.06 (s, 2H), 4.66 (s, 2H); LRMS calcd forC₂₄H₁₅F₃N₂O₂S: 452.0. found 453.0 (M+1)⁺. Anal. Calcd for C₂₄H₁₅F₃N₂O₂S:C, 63.71; H, 3.34; N, 6.19; S, 7.09. Found: C, 63.54; H, 3.32; N, 6.13;S, 7.01.

Example 16 Preparation of6-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acidStep 1: 6-Phenylindole

A solution of 6-bromoindole (2.0 g, 10.20 mmol) in anhydrous toluene (20mL) under a nitrogen atmosphere was treated with Pd[P(Ph₃)]₄ (10% mol).After stirring the mixture for 30 min., phenylboronic acid (1.87 g,15.30 mmol) in anhydrous EtOH (10 mL) was added followed by the additionof sat'd NaHCO₃ (6 mL). The bi-phasic mixture was heated to reflux for24 h. After cooling to room temperature, the mixture was added to asat'd brine solution and extracted with EtOAc (2×). The organic layerwas dried over MgSO₄, filtered and concentrated in vacuo. The residuewas purified by flash column chromatography (1:1 CH₂Cl₂/heptane) to givethe desired material as white powder (900 mg, 45%): ¹H NMR (DMSO-d₆, 300MHz) δ 11.15 (br s, 1H), 7.58-7.66 (m, 4H), 7.41-7.47 (m, 2H), 7.36 (m,1H), 7.26-7.31 (m, 2H), 6.42 (m, 1H).

Preparation of 6-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methylindole-N-acetic acid6-phenyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acidwas prepared in a manner analogous to that set forth in Example 2,except that 6-phenylindole was used instead of 5-chloroindole in step 1:mp 156-159° C.; R_(f) 0.50 (10% methanol in chloroform); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.65-7.75 (m, 4H), 7.57-7.62 (m, 1H), 7.41-7.50 (m,3H), 7.26-7.38 (m, 2H), 5.12 (s, 2H), 4.68 (s, 2H); LRMS calcd forC₂₄H₁₅F₃N₂O₂S: 452.0. found 453.0 (M+1)⁺. Anal. Calcd for C₂₄H₁₅F₃N₂O₂S:C, 63.71; H, 3.34; N, 6.19; S, 7.09. Found: C, 63.46; H, 3.33; N, 6.10;S, 6.96.

Example 17 Preparation of5-morpholino-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid

5-Morpholino-2-nitrotoluene

A mixture of 5-fluoro-2-nitrotoluene (5.11 g, 32.9 mmol), morpholine(4.31 mL, 49.4 mmol) and K₂CO₃ (6.83 g, 49.4 mmol) was diluted inanhydrous DMSO (80 mL) at room temperature with stirring. The mixturewas heated to 80° C. for 24 h. After cooling to room temperature, H₂Owas added and the resultant mixture was extracted with EtOAc (3×, 50mL). The organic layer was washed with sat'd aqueous NaCl (100 mL),dried over MgSO₄, filtered and concentrated in vacuo. The remainingsolid was triturated in heptane (200 mL) and filtered to give thedesired material (7.10 g, 97%) as a yellow powder: R_(f) 0.40 (75%heptane/25% ethyl acetate). ¹H NMR (DMSO-d₆, 300 MHz) δ 7.96 (d, J=9.9Hz, 1H), 8.85-8.88 (m, 2H), 3.70 (t, J=5.0 Hz, 4H), 3.35 (t, J=5.0 Hz,4H), 2.53 (s, 3H).

Preparation of 5-Morpholinoindole

Under an atmosphere of nitrogen, a solution of5-morpholinyl-2-nitrotoluene (7.0 g, 31.5 mmol) in DMF (100 mL) wastreated with dimethylformamide dimethyl acetal (4.81 mL, 36.2 mmol) andpyrrolidine (2.62 mL, 31.5 mL). The mixture was heated to 100° C. andmaintained for 12 h. After cooling, the mixture was concentrated invacuo to give the desired intermediate as a brick-red solid.

The intermediate enamine was dissolved in EtOAc (200 mL) and added to apre-charged Parr bottle with 10% Pd/C (600 mg) in EtOAc (40 mL). Themixture was hydrogenated on a Parr-shaker at 55 psi for 2.5 h. Thecatalyst was filtered through a Celite plug with several washings withEtOAc and the remaining filtrate concentrated in vacuo. The residue waspurified by SiO₂ flash chromatography (1:1 Hept/EtOAc) to give 2.0 g(31% over 2 steps) of the desired indole as a cream powder: R_(f) 0.30(10% methanol in chloroform); ¹H NMR (DMSO-d₆, 300 MHz) δ 10.77 (br s,1H), 7.24 (s, 1H), 7.18-7.20 (m, 1H), 6.97 (d, J=1.8 Hz, 1H), 6.81 (dd,J₁=8.7 Hz, J₂=2.1 Hz, 1H), 6.25 (dd, J₁=3.0 Hz, J₂=1.8 Hz, 1H), 3.7 (t,J=4.50 Hz, 4H), 2.96 (t, J=4.50 Hz, 4H).

Preparation of 5-morpholino-3(4,5,7-trifluorobenzothiazol-2-yl)methylindole-N-acetic acid

5-morpholino-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl indole-N-aceticacid was prepared in a manner analogous to that set forth in Example 2,except that 5-morpholinoindole was used instead of 5-chloroindole. ¹HNMR (DMSO-d₆, 300 MHz) δ 7.64-7.72 (m, 1H), 7.34 (s, 1H), 7.26 (d, J=9.0Hz, 1H), 7.06 (d, J=2.4 Hz, 1H), 6.91 (dd, J₁=9.0 Hz, J₂=2.4 Hz, 1H),4.95 (s, 2H), 4.60 (s, 2H), 3.70-3.73 (m, 4H), 2.97-3.00 (m, 4H); LRMScalcd for C₂₂H₁₈F₃N₃O₃S: 461.0. found 462 (M+1)⁺. Anal. Calcd forC₂₂H₁₈F₃N₃O₃S.1H₂O: C, 55.11; H, 4.20; N, 8.76; S, 6.69. Found: C,55.11; H, 4.05; N, 8.57; S, 6.50.

Example 18 Preparation of6-morpholino-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid Preparation of 4-Morpholino-2-nitrotoluene

A mixture of 4-fluoro-2-nitrotoluene (15.34 g, 98.9 mmol), morpholine(12.94 mL, 49.4 mmol) and K₂CO₃ (6.83 g, 148.3 mmol) were diluted inanhydrous DMSO (250 mL) at room temperature with stirring. The mixturewas heated to 120° C. for 24 h. After cooling to room temperature, H₂Owas added and the resultant mixture was extracted with EtOAc (3×, 75mL). The organic layer was washed with sat'd brine (100 mL), dried overMgSO₄, filtered and concentrated in vacuo. The remaining solid wastriturated in hepatane (200 mL) and filtered to give the desiredmaterial (8.00 g, 36.4%) as a yellow powder: R_(f) 0.40 (25% ethylacetate in heptane). ¹H NMR (DMSO-d₆, 300 MHz) δ 7.40 (d, J=2.7 Hz, 1H),7.30 (d, J=8.7 Hz, 1H), 7.20 (dd, J₁=8.7 Hz, J₂=2.7 Hz, 1H), 3.70 (t,J=4.8 Hz, 4H), 3.35 (t, J=4.8 Hz, 4H), 2.36 (s, 3H).

Preparation of 6-Morpholinoindole

Under an atmosphere of nitrogen, a solution of4-morpholino-2-nitrotoluene (7.1 g, 31.9 mmol) in DMF (100 mL) wastreated with dimethylformamide dimethyl acetal (4.92 mL, 37.1 mmol) andpyrrolidine (2.67 mL, 31.9 mL). The mixture was heated to 100° C. andmaintained for 12 h. After cooling, the mixture was concentrated invacuo to give the desired intermediate as a brick-red solid. The crudeintermediate was dissolved in glacial HOAc (250 mL) and warmed to 85° C.Zn (18.17 g, 0.278 mol) was added to the solution portionwise over 30min. The mixture was heated for 4 h. After cooling to room temperature,the mixture was neutralized with sat'd NaHCO₃ and extracted with Et₂O(3×, 300 mL). The combined organics were washed with sat'd brine, driedover MgSO₄, filtered and concentrated in vacuo. The residue was purifiedby SiO₂ flash chromatography (heptane to 2:1 heptane/EtOAc) to give thedesired material as a white crystalline powder (1.0 g, 11% over 2steps): R_(f) 0.50 (2:1 Heptane/EtOAc); ¹H NMR (DMSO)-d₆, 300 MHz) δ10.73 (br s, 1H), 7.35 (d, J=8.4 Hz, 1H), 7.11 (d, J=2.4 Hz, 1H), 6.80(s, 1H), 6.73 (dd, J₁=8.4 Hz, J₂=2.4 Hz, 1H), 6.25 (d, J=2.4 Hz, 1H),3.72 (t, J=4.8 Hz, 4H), 3.02 (t, J=4.8 Hz, 1H).

Preparation of 6-morpholino-3-(4,5,7-trifluorobenzothiazol-2-yl)methylindole-N-acetic acid

6-morpholino-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl indole-N-aceticacid was prepared in a manner analogous to that set forth in Example 2,except that 6-morpholinoindole was used instead of 5-chloroindole instep 1: mp 178-180° C.; ¹H NMR (DMSO-d₆, 300 MHz) δ 7.66-7.72 (m, 1H),7.37 (d, J=8.4 Hz, 1H), 7.29 (s, 1H), 7.06 (d, J=2.4 Hz, 1H), 6.84 (d,J=8.4 Hz, 1H), 4.96 (s, 2H), 4.58 (s, 2H), 3.37-3.75 (m, 4H), 3.09-3.13(m, 4H); LRMS calcd for C₂₂H₁₈F₃N₃O₃S: 461.0. found 462 (M+1)⁺. Anal.Calcd for C₂₂H₁₈F₃N₃O₃S CH₂Cl₂ 0.50H₂O: C, 49.74; H, 3.72; N, 7.57; S,5.77

Found C, 49.73; H, 3.36; N, 7.69; S, 5.58

Example 19 Preparation of5-phenoxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid

5-Phenoxy-2-nitrotoluene

A solution of phenol (12.16 g, 0.129 mol) in anhydrous DMSO was treatedwith K₂CO₃ (17.88 g, 0.129 mol) and stirred at room temperature for 15min. 5-Fluoro-2-nitrotoluene (13.38 g, 0.086 mol) was added to thesolution via syringe. The resultant mixture was heated to 80° C. for 12h. After cooling to room temperature, the mixture was poured into H₂O(100 mL). After extraction with EtOAc (2×, 100 mL), the organics werecombined and washed with a sat'd brine solution, dries over MgSO₄,filtered and concentrated in vacuo. The residue was purified by flashcolumn chromatography (heptane to 8:1 heptane/EtOAc) to give the desiredmaterial as a yellow crystalline solid (12.50 g, 63%): R_(f) 0.60 (85%heptane/15% EtOAc); ¹H NMR (DMSO-d₆, 300 MHz) δ 8.05 (d, J=9.0 Hz, 1H),7.44-7.47 (m, 2H), 7.23-7.29 (m, 1H), 7.12-7.16 (m, 2H), 7.04 (d, J=2.7Hz, 1H), 6.90 (dd, J₁=9.0 Hz, J₂=2.7 Hz, 1H), 2.51 (s, 3H).

5-Phenoxyindole

A solution of 5-phenoxy-2-nitrotoluene (10.03 g, 0.0428 mol) inanhydrous DMF was treated with N,N-dimethylformamide dimethyl diacetal(6.73 mL, 0.0508 mol) and pyrrolidine (3.63 mL, 0.0438 mol) and heatedto 110° C. for 2.5 h. After cooling to room temperature, the mixture wasdiluted with EtOAc (500 mL) and washed H₂O (500 mL). The organics weredried over MgSO₄, filtered and concentrated in vacuo. The crudeintermediate was dissolved in glacial HOAc (250 mL) and warmed to 85° C.Zn (24.62 g, 0.377 mol) was added to the solution portion wise over 30min. The mixture was heated for 4 h. After cooling to room temperature,the mixture was neutralized with sat'd NaHCO₃ and extracted with Et₂O(3×, 300 mL). The combined organics were washed with sat'd brine, driedover MgSO₄, filtered and concentrated in vacuo. The residue was purifiedby SiO₂ flash chromatography (heptane to 2:1 heptane/EtOAc) to give thedesired material as a white crystalline powder (3.1 g, 34% over 2steps): R_(f) 0.50 (2:1 Heptane/EtOAc); ¹H NMR (DMSO-d₆, 300 MHz) δ11.12 (br s, 1H), 7.48 (s, 1H), 7.30-7.38 (m, 1H), 7.25-7.29 (m, 2H),7.17 (d, J=2.7 Hz, 1H), 6.89-7.02 (m, 1H), 6.86-6.88 (m, 2H), 6.80 (dd,J₁=8.7 Hz, J₂=2.4 Hz, 1H), 6.37 (m, 1H).

Preparation of 5-phenoxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methylindole-N-acetic acid

5-phenoxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl indole-N-aceticacid was prepared in a manner analogous to that set forth in Example 2,except that 5-phenoxyindole was used instead of 5-chloroindole in step1: mp 128-130° C.; R_(f) 0.45 (10% methanol in chloroform); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.65-7.70 (m, 1H), 7.47 (s, 1H), 7.42 (d, J=8.4 Hz,1H), 7.21-7.27 (m, 3H), 6.98 (m, 1H), 6.83-6.90 (m, 3H), 5.02 (s, 2H),4.60 (s, 2H); LRMS calcd for C₂₄H₁₅F₃N₂O₃S: 468.0. found 467.0 (M−1)⁻.Anal. Calcd for C₂₄H₁₅F₃N₂O₃S: C, 55.11; H, 4.20; N, 8.76; S, 6.69.Found: C, 55.11; H, 4.05; N, 8.57; S, 6.50.

Example 20 Preparation of7-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

7-Fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl indole-N-acetic acidwas prepared in a manner analogous to that set forth in Example 2,except that 7-fluoroindole was used instead of 5-chloroindole in step 1:mp 194-196° C.; R_(f) 0.60 (10% methanol in chloroform); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.67-7.73 (m, 1H), 7.46 (s, 1H), 7.35 (d, J=7.2 Hz,1H), 6.89-6.99 (m, 2H), 5.06 (s, 2H), 4.64 (s, 2H); LRMS calcd forC₁₈H₁₀F₄N₂O₂S.H₂O: C, 50.23; H, 3.28; N, 6.51; S, 7.45. Found C, 50.70;H, 2.52; N, 6.60; S, 7.57. 394.0. found 395.0 (M+1)⁺. Anal. Calcd forC₁₈H₁₀F₄N₂O₂S

Example 21 Preparation of7-bromo-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

7-bromo-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl indole-N-acetic acidwas prepared in a manner analogous to that set forth in Example 2,except that 7-bromoindole was used instead of 5-chloroindole in step 1:mp 228-230° C.; R_(f) 0.40 (10% methanol in chloroform); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.65-7.74 (m, 1H), 7.57 (d, J=7.8 Hz, 1H), 7.49 (s,1H), 7.32 (d, J=7.8 Hz, 1H), 6.94 (t, J=7.8 Hz, 1H), 5.29 (s, 2H), 4.65(s, 2H); LRMS calcd for C₁₈H₁₀F₃N₂O₂SBr: 454.0 for (⁷⁹Br and 456.0 for⁸¹Br). found 453.0 (M−1)⁻ and 455.0 (M−1)⁻. Anal Calcd forC₁₈H₁₀F₃N₂O₂SBr: C, 47.49; H, 2.21; N, 6.15; S, 7.04. Found: C, 47.65;H, 2.27; N, 6.15; S, 6.98.

Example 22 Preparation of7-chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

7-chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl indole-N-acetic acidwas prepared in a manner analogous to that set forth in Example 2,except that 7-chloroindole was used instead of 5-chloroindole in step 1:mp 228-230° C.; R_(f) 0.38 (10% methanol in chloroform); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.62-7.73 (m, 1H), 7.52 (d, J=7.5 Hz, 1H), 7.49 (s,1H), 7.15 (d, J=7.5 Hz, 1H), 7.00 (t, J=7.5 Hz, 1H), 5.25 (s, 2H), 4.65(s, 2H); LRMS calcd for C₁₈H₁₀F₃N₂O₂SCl: 410.0. found 409.0 (M−1)⁻.Anal. Calcd for C₁₈H₁₀F₃N₂O₂SCl: C, 52.63; H, 2.45; N, 6.82; S, 7.81.Found: C, 52.60; H, 2.54; N, 6.66; S, 7.59.

Example 23 3-[5-Fluorbenzothiazole-2-yl]methyl-indole-N-acetic Acid

3-[5-fluorbenzothiazole-2-yl]methyl-indole-N-acetic acid was prepared ina manner analogous to that set forth in Example 3, except2-amino-4-fluorothiophenol hydrochloride was used instead of2-amino-4,5,7-trifluorothiophenol hydrochloride in step 6: mp 208° C.(decomp); R_(f)0.10 (10% methanol in diehloromethane)¹H NMR (DMSO-d₆,300 MHz) δ 12.91 (s, 1H), 7.98 (dd, J=8.9, 5.6 Hz: 1 H), 7.78 (dd,J=10.0, 2.6 Hz, 1H), 7.50 (d, J=7.8 Hz, 1H), 7.40 (s, 1H), 7.37 (d,J=7.8 Hz, 1H), 7.26 (dt, J=8.9, 2.4 Hz, 1H), 7.13 (t, J=7.8 Hz, 1H),7.01 (t, J=7.8 Hz, 1H), 5.01 (s, 2H), 4.56 (s, 2H); LRMS m/z 341.0(M+1)⁺, 339.0 (M−1). Anal. Calcd for C₁₈H₁₃FN₂O₂S: C, 63.52; H, 3.85; N,8.23; S, 9.42. Found: C, 63.40; H, 3.80; N, 8.37; S, 9.43.

Example 24 3-[6-Fluorbenzothiazole-2-yl]methyl-indole-N-acetic Acid

3-[6-fluorbenzothiazole-2-yl]methyl-indole-N-acetic acid was prepared ina manner analogous to that set forth in Example 3, except2-amino-5-fluorothiophenol hydrochloride was used instead of2-amino-4,5,7-trifluorothiophenol hydrochloride in step 6: mp 203° C.(decomp) R_(f)0.13 (10% methanol in diehloromethane); ¹H NMR (DMSO-d₆,300 MHz) δ 12.91 (s, 1H), 7.95 (dd, J=8.9, 5.0 Hz: 1 H), 7.86 (dd,J=8.8, 2.8 Hz, 1H), 7.50 (d, J=7.5 Hz, 1H), 7.40-7.35 (m, 2H), 7.32 (dt,J=8.9, 2.7 Hz, 1H), 7.13 (t, J=7.6 Hz, 1H), 7.00 (t, J=7.6 Hz, 1H), 5.01(s, 2H), 4.54 (s, H); LRMS m/z 341.0 (M+1)⁺, 339.0 (M−1. Anal. Calcd forC₁₈H₁₃FN₂O₂S: C, 63.52; H, 3.85; N, 8.23; S, 9.42. Found: C, 63.52; H,3.86; N, 8.35; S, 9.53.

The compounds of Examples 25-32 were prepared essentially according tothe procedures set forth above in examples land/or 2 with appropriatesubstitution of starting materials.

Example 253-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-2-propionic acid

mp 176-177° C.; R_(f) 0.34 (20% methanol in dichlormethane); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.60-7.73 (m, 1H), 7.60 (s, 1H), 7.52 (d, J=8.1 Hz,1H), 7.44 (d, J=8.1 Hz, 1H), t, J=7.5 Hz, 1H), 7.02 (t, J=7.5 Hz, 1H),5.35 (q, J=8.1 Hz, 1H), 4.64 (s, 2H), 1.72 (d, J=8.1 Hz, 3H); LRMS calcdfor C₁₉H₁₃F₃N₂O₂S: 390.0. Found 391.0 (M 1)⁺. Anal. Calcd forC₁₉H₁₃F₃N₂O₂SH₂O: C, 55.88; H, 3.70; N, 6.86; S, 7.85 Found: C, 56.09;H, 3.31; N, 6.89; S, 7.99.

Example 263-(4-5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-3-propionic acid

mp 200-201° C.; R_(f) 0.50 (20% methanol in dichloromethane); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.63-7.71 (m, 1H), 7.51 (s, 1H), 7.47 (d, J=3.0 Hz,2H), 7.14 (t, J=7.5 Hz, 1H), 7.00 (t, J=7.5 Hz, 1H), 4.61 (s, 2H), 4.39(t, J=6.6 Hz, 2H), 2.75 (t, J=6.6 Hz, 2H); LRMS calcd for C₁₉H₁₃F₃N₂O₂S:390.0. Found 391.0 (M+1)⁺. Anal Calcd for C₁₉H₁₃F₃N₂O₂S: C, 58.46; H,3.36; N, 7.18; S, 8.21 Found: C, 58.63; H, 3.40; N, 7.20; S, 8.30.

Example 27 Preparation of6-Bromo-3-(5-trifluoromethylbenzothiazol-2-yl)methyl-indole-N-aceticacid

mp 265-267° C.; R_(f) 0.19 (20% methanol in dichloromethane); ¹H NMR(DMSO-d₆, 300 MHz) δ 8.28 (s, 1H), 8.22 (d, J=8.7 Hz, 1H), 7.67-7.69 (m,2H), 7.43-7.47 (m, 2H), 7.14 (d, J=9.0 Hz, 1H), 5.04 (s, 2H), 4.61 (s,2H); LRMS calcd for C₁₉H₁₂F₃N₂O₂SBr:469.0. Found 469.0 (M+1)⁺ for Br=79.Anal. Calcd for C₁₉H₁₂F₃N₂O₂SBr: C, 48.63; H, 2.58; N, 5.97; S, 6.83.Found: C, 48.60; H, 2.63; N, 5.88; S, 6.91.

Example 286-Methoxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid

mp 118-120° C.; R_(f) 0.27 (20% methanol in dichloromethane); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.63-7.73 (m, 1H), 7.39 (s, 1H), 7.28 (d, J=8.7 Hz,1H), 7.07 (s, 1H), 6.78 (d, J=8.7 Hz, 1H), 4.97 (s, 2H), 4.61 (s, 2H);3.07 (s, 3H); LRMS calcd for C₁₉H₁₃F₃N₂O₃S: 406.0. Found 407.0 (M⁺)⁺.Anal. Calcd for C₁₉H₁₃F₃N₂O₃SH₂O: C, 53.77; H, 3.56; N, 6.60; S, 7.56Found: C, 53.87; H, 3.56; N, 6.67; S, 7.67.

Example 294-Chloro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

mp 203-206° C.; R_(f) 0.24 (20% methanol in dichloromethane); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.63-7.71 (m, 1H), 7.57 (s, 1H), 7.33 (d, J=9.0 Hz,1H), 7.12 (dd, J (₁)=9.0, J (₂)=7.8 Hz, 1H), 7.03 (d, J=7.8 Hz, 1H),5.08 (s, 2H), 4.78 (s, 2H); LRMS calcd for C₁₈H₁₀F₃N₂O₂SCl: 410.0. Found411.0 (M+1)⁺ and 409.0 (M−1)⁻.

Example 305-Methoxy-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid

mp 165-167° C.; R_(f) 0.37 (20% methanol in dichloromethane); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.61-7.70 (m, 1H), 7.35 (d, J=9.0 Hz, 1H), 7.26 (s,1H), 6.90 (s, 1H), 6.64 (d, J=9.0 Hz, 1H), 4.79 (s, 2H); 4.56 (s, 2H),3.72 (s, 3H); LRMS calcd for C₁₀H₁₃F₃N₂O₂S: 406.0. Found 407.0 (M+1)⁺and 405.0 (M−1)⁻.

Example 315-Bromo-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid

mp 209-294° C.; R_(f) 0.18 (20% methanol in dichloromethane); ¹H NMR(DMSO-d₆, 300 MHz) δ 7.78 (d, J=1.8 Hz, 1H), 7.65-7.73 (m, 1H), 7.49 (s,1H), 7.61 (d, J=9.0 Hz, 1H), 7.25 (dd, J (₁)=9.0 Hz, J (₂)=1.8 Hz, 1H),5.04 (s, 2H); 4.64 (s, 2H); LRMS calcd for C₁₈H₁₀F₃N₂O₂SBr: 455.0. Found455.0 (M+1)⁺ for Br 79 and 457 (M+1)⁺ for Br 81.

Example 32 3-(6-chlorobenzothiazol-2-yl)methyl-indole-N-acetic acid

Representative compounds of the invention were tested for their potency,selectivity and efficacy as inhibitors of human aldose reductase. Thepotency or aldose reductase inhibiting effects of the compounds weretested using methods similar to those described by Butera et al. in J.Med. Chem. 1989, 32, 757. Using this assay, the concentrations requiredto inhibit human aldose reductase (hALR2) activity by 50% (IC50) weredetermined.

In a second assay, a number of the same compounds were tested for theirability to inhibit aldehyde reductase (hALR1), a structurally relatedenzyme. The test method employed were essentially those described byIshii, et al., J. Med. Chem. 1996 39: 1924. Using this assay, theconcentrations required to inhibit human aldehyde reductase activity by50% (IC50) were determined.

From these data, the hALR1/hALR2 ratios were determined. Since highpotency of test compounds as inhibitors of aldose reductase isdesirable, low hALR2 IC₅₀ values are sought. On the other hand, highpotency of test compounds as inhibitors of aldehyde reductase isundesirable, and high hALR1 IC₅₀s values are sought. Accordingly, thehALR1/hALR2 ratio is used to determine the selectivity of the testcompounds. The importance of this selectivity is described in Kotani, etal., J. Med. Chem. 40: 684, 1997.

The results of all these tests are combined and illustrated in Table 1.

Example hALR2 HALR1 HALR1/ # (IC50) (IC50) hALR2 1 8 nM 13,000 nM 1,2002 10 nM 11,000 nM 1,100 3 5 nM 27,000 nM 5,400 4 8 nM 34,000 nM 4,250 56 nM 21,000 nM 3,500 6 8 nM 2,700 nM 340 7 12 nM 4,800 nM 400 8 7 nM7,500 nM 1,100 9 11 nM 21,000 nM 1,900 10 5 nM 13,000 nM 2,600 11 99 nM5,600 nM 57 12 102 nM 10,000 nM 98 13 73 nM 13,000 nM 178 14 101 nM16,000 160 15 53 nM 10,000 190 16 25 nM 6,200 nM 248 17 8 nM 41,000 nM5,100 18 15 nM >100 μM >6,700 19 30 nM 11,000 nM 370 20 7 nM 7,000 nM1,000 21 14 nM 18,000 nM 1,300 22 9.1 nM 19,000 nM 2,100 23 9 nM 6,500nM 720 24 1,040 nM 4,500 nM 4 25 160 nM 6,500 nM 41 26 17 nM 88,000 nM5,200 27 52 nM <5,000 nM <96 28 5 nM 12,000 nM 2,400 29 11 nM 14,0001,270 30 7.7 nM 21,000 nM 2,700 31 13 nM 9,700 746 32 660 nM Not TestedNot Tested Tolrest at 13 nM 1,940 nM 149

The results show the superior potency, selectivity and efficacy ofrepresentative compounds of the invention. Such compounds are useful inthe treatment of chronic complications arising from diabetes mellitus,such as diabetic cataracts, retinopathy and neuropathy. Accordingly, anaspect of the invention is treatment of such complications with theinventive compounds; treatment includes both prevention and alleviation.The compounds are useful in the treatment of, for example, diabeticcataracts, retinopathy, nephropathy and neuropathy.

In a third, optional, set of experiments, the compounds can be assayedfor their ability to normalize or reduce sorbitol accumulation in thesciatic nerve of streptozotocin-induced diabetic rats. The test methodsemployed to determine the efficacy are essentially those of Mylari, etal., J. Med. Chem. 34: 108, 1991.

The invention and the manner and process of making and using it, are nowdescribed in such full, clear, concise and exact terms as to enable anyperson skilled in the art to which it pertains, to make and use thesame. It is to be understood that the foregoing describes preferredembodiments of the present invention and that modifications may be madetherein without departing from the spirit or scope of the presentinvention as set forth in the claims. To particularly point out anddistinctly claim the subject matter regarded as invention, the followingclaims conclude this specification.

1. A compound of the formula:

or a pharmaceutically acceptable salt thereof, wherein A is C₁-C₄ alkyl;Z is a bond; R₁ is hydrogen, halogen, or alkyl having 1-6 carbon atoms;R₃ is hydrogen, alkyl group of 1-6 carbon atoms, or halogen; R₂, R₄ andR₅ are independently hydrogen or halogen; R₆ is hydroxy; R_(a) ishydrogen; and Ar represents a heterocyclic 5-membered ring having onenitrogen, two nitrogens one of which may be replaced by sulfur, saidheterocyclic 5-membered ring optionally being condensed with benzo, saidbenzo being optionally substituted by one of iodo, cyano, nitro,perfluoroethyl, trifluoroacetyl, or (C₁-C₆)alkanoyl, one or two offluoro, chloro, bromo, hydroxy, (C₁-C₆)alkyl, (C₁-C₆)alkoxy,(C₁-C₆)alkylthio, trifluoromethoxy, trifluoromethylthio,(C₁-C₆)alkylsulfinyl, (C₁-C₆)alkylsulfonyl or trifluoromethyl, or twofluoro or two trifluoromethyl with one hydroxy or one (C₁-C₆)alkoxy, orone or two fluoro and one trifluoromethyl, or three flour; or aheterocyclic 6-membered ring having one to two nitrogen atoms, or onenitrogen atom and sulfur, said heterocyclic 6-membered ring optionallybeing condensed with benzo, said benzo being optionally substituted byone of iodo or trifluoromethylthio, or one or two of fluoro, chloro,bromo, (C₁-C₆)alkyl, (C₁-C₆)alkoxy, (C₁-C₆)alkylthio,(C₁-C₆)alkylsulfinyl, (C₁-C₆)alkylsulfonyl, or trifluoromethyl, and saidpyridyl, furyl or thienyl optionally substituted in the 3-position byfluoro, chloro, (C₁-C₆)alkyl or (C₁-C₆)alkoxy.
 2. A compound accordingto claim 1, wherein Ar represents benzothiazolyl, quinolinyl,isoquinolinyl, quinoxalyl, or thiazolyl, each of which is optionallysubstituted with one of iodo, cyano, nitro, perfluoroethyl,trifluoroacetyl, or (C₁-C₆)alkanoyl, one or two of fluoro, chloro,bromo, hydroxy, (C₁-C₆)alkyl, (C₁-C₆)alkoxy, (C₁-C₆)alkylthio,trifluoromethoxy, trifluoromethylthio, (C₁-C₆)alkylsulfinyl,(C₁-C₆)alkylsulfonyl or trifluoromethyl, or two fluoro or twotrifluoromethyl with one hydroxy or one (C₁-C₆)alkoxy, or one or,preferably, two fluoro and one trifluoromethyl, or three fluoro; orphenyl group optionally substituted with up to 5 groups independentlyselected from halogen, an alkyl group of 1-6 carbon atoms (which may besubstituted with one or more halogens), nitro, OR₇, SR₇, S(O)R₇, S(O)₂R₇or N(R₇)₂ wherein R₇ is hydrogen, an alkyl group of 1-6 carbon atoms(which may be substituted with one or more halogens) or benzyl, wherethe phenyl portion is optionally substituted with up to three groupsindependently selected from halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, amino,and mono- or di(C₁-C₆)alkylamino.
 3. A compound according to claim 2,wherein Ar is benzothiazolyl, quinolinyl, isoquinolinyl, quinoxalyl, orthiazolyl, each of which is optionally substituted with onetrifluoromethyl or up to three fluoro groups.
 4. A compound according toclaim 1 wherein at least one of R₁ and R₃ is not hydrogen;
 5. A compoundaccording to claim 1 wherein R₂, R₄ and R₅ are all hydrogen.
 6. Acompound according to claim 1 wherein R₁ is hydrogen or alkyl having 1-6carbon atoms.
 7. A compound according to claim 5, wherein R₁ is hydrogenor methyl.
 8. A compound of the formula:

or a pharmaceutically acceptable salt thereof, wherein A is methylene; Zis a bond; R₁ is hydrogen or alkyl having 1-6 carbon atoms; R₃ ishydrogen or halogen; provided that at least one of R₁ and R₃ is nothydrogen; R₂, R₄ and R₅ are all hydrogen; R₆ is hydroxy; R_(a) ishydrogen; and Ar represents benzothiazolyl, quinolinyl, isoquinolinyl,quinoxalyl, or thiazolyl, each of which is optionally substituted withone of iodo, cyano, nitro, perfluoroethyl, trifluoroacetyl, or(C₁-C₆)alkanoyl, one or two of fluoro, chloro, bromo, hydroxy,(C₁-C₆)alkyl, (C₁-C₆)alkoxy, (C₁-C₆)alkylthio, trifluoromethoxy,trifluoromethylthio, (C₁-C₆)alkylsulfinyl, (C₁-C₆)alkylsulfonyl ortrifluoromethyl, or two fluoro or two trifluoromethyl with one hydroxyor one (C₁-C₆)alkoxy, or one or, preferably, two fluoro and onetrifluoromethyl, or three fluoro; or phenyl group optionally substitutedwith up to 5 groups independently selected from halogen, an alkyl groupof 1-6 carbon atoms (which may be substituted with one or morehalogens), nitro, OR₇, SR₇, S(O)R₇, S(O)₂R₇ or N(R₇)₂ wherein R₇ ishydrogen, an alkyl group of 1-6 carbon atoms (which may be substitutedwith one or more halogens) or benzyl, where the phenyl portion isoptionally substituted with up to three groups independently selectedfrom halogen, C₁-C₆ alkyl, C₁-C₆ alkoxy, amino, and mono- ordi(C₁-C₆)alkylamino.
 9. A compound according to claim 6, where R₁ ishydrogen or methyl.
 10. A compound according to claim 8, wherein Ar isbenzothiazolyl, quinolinyl, isoquinolinyl, quinoxalyl, or thiazolyl,each of which is optionally substituted with one trifluoromethyl or upto three fluoro groups.
 11. A compound according to claim 8, wherein Aris phenyl substituted with one group.
 12. A compound according to claim8, wherein Ar is phenyl substituted with SO₂R₇.
 13. A compound accordingto claim 1, which is:2-methyl-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid;5-chloro-3-(4,5,7-Trifluorobenzothiazol-2-yl)methyl-indole-N-aceticAcid;5-fluoro-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-aceticacid; 3-(3-nitrophenyl)methyl-indole-N-acetic acid;5-Methyl-3-(5-Trifluoromethylbenzothiazol-2-yl)methyl-indole-N-aceticacid or5-Bromo-3-(4,5,7-trifluorobenzothiazol-2-yl)methyl-indole-N-acetic acid.14. A compound of general formula (I):

wherein R¹, R³ and R⁴ are hydrogen; R² is halo; R⁵ and R⁶ are hydrogen;R⁷ is C₁-C₆alkyl; R⁸ is a phenyl, naphthalenyl, thiazole, biphenyl,quinolinyl or quinoxalinyl group, any of which may be substituted withone or more halo, C₁-C₆ alkyl, —O(C₁-C₆)alkyl, —SO₂R¹¹, or —OH groups;wherein R¹¹ is independently hydrogen or C₁-C₆ alkyl; R⁹ is hydrogen; ora pharmaceutically acceptable salt thereof.
 15. The compound of claim14, wherein, R² is fluoro; and R⁷ methyl.
 16. A pharmaceuticalcomposition comprising a compound of claim 14 together with apharmaceutical excipient or carrier.
 17. A pharmaceutical composition,comprising a compound of claim 15 together with a pharmaceuticalexcipient or carrier.